If you want to **know** about my **latest modifications**/**additions** or you have **any suggestion for HackTricks or PEASS**, **join the** [**💬**](https://emojipedia.org/speech-balloon/) ****[**PEASS & HackTricks telegram group here**](https://t.me/peass), or **follow me on Twitter** [🐦](https://emojipedia.org/bird/)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
If you want to **share some tricks with the community** you can also submit **pull requests** to [https://github.com/carlospolop/hacktricks](https://github.com/carlospolop/hacktricks**]%28https://github.com/carlospolop/hacktricks) **that will be reflected in this book.
You can find a good vulnerable kernel list and some already **compiled exploits** here: [https://github.com/lucyoa/kernel-exploits](https://github.com/lucyoa/kernel-exploits) and [exploitdb sploits](https://github.com/offensive-security/exploitdb-bin-sploits/tree/master/bin-sploits).
Other sites where you can find some **compiled exploits**: [https://github.com/bwbwbwbw/linux-exploit-binaries](https://github.com/bwbwbwbw/linux-exploit-binaries), [https://github.com/Kabot/Unix-Privilege-Escalation-Exploits-Pack](https://github.com/Kabot/Unix-Privilege-Escalation-Exploits-Pack)
To extract all the vulnerable kernel versions from that web you can do:
[linuxprivchecker.py](http://www.securitysift.com/download/linuxprivchecker.py) \(execute IN victim,only checks exploits for kernel 2.x\)
Always **search the kernel version in Google**, maybe your kernel version is wrote in some kernel exploit and then you will be sure that this exploit is valid.
Also, check if **any compiler is installed**. This is useful if you need to use some kernel exploit as it's recommended to compile it in the machine where you are going to use it \(or in one similar\)
Check for the **version of the installed packages and services**. Maybe there is some old Nagios version \(for example\) that could be exploited for escalating privileges…
_Note that these commands will show a lot of information that will mostly be useless, therefore it's recommended some application like OpenVAS or similar that will check if any installed software version is vulnerable to known exploits_
Take a look to **what processes** are being executed and check if any process has **more privileges that it should** \(maybe a tomcat being executed by root?\)
Always check for possible [**electron/cef/chromium debuggers** running, you could abuse it to escalate privileges](electron-cef-chromium-debugger-abuse.md). **Linpeas** detect those by checking the `--inspect` parameter inside the command line of the process.
You can use tools like [**pspy**](https://github.com/DominicBreuker/pspy) to monitor processes. This can be very useful to identify vulnerable processes being executed frequently or when a set of requirements are met.
Some services of a server save **credentials in clear text inside the memory**.
Normally you will need **root privileges** to read the memory of processes that belong to other users, therefore this is usually more useful when you are already root and want to discover more credentials.
However, remember that **as a regular user you can read the memory of the processes you own**.
#### GDB
If you have access to the memory of a FTP service \(for example\) you could get the Heap and search inside of it the credentials.
For a given process ID, **maps shows how memory is mapped within that processes'** virtual address space; it also shows the **permissions of each mapped region**. The **mem** pseudo file **exposes the processes memory itself**. From the **maps** file we know which **memory regions are readable** and their offsets. We use this information to **seek into the mem file and dump all readable regions** to a file.
`/dev/mem` provides access to the system's **physical** memory, not the virtual memory. The kernels virtual address space can be accessed using /dev/kmem.
* [**https://github.com/hajzer/bash-memory-dump**](https://github.com/hajzer/bash-memory-dump) \(root\) - _You can manually remove root requirements and dump process owned by you_
The tool [**https://github.com/huntergregal/mimipenguin**](https://github.com/huntergregal/mimipenguin) will **steal clear text credentials from memory** and from some **well known files**. It requires root privileges to work properly.
Check if any scheduled job is vulnerable. Maybe you can take advantage of a script being executed by root \(wildcard vuln? can modify files that root uses? use symlinks? create specific files in the directory that root uses?\).
If the script executed by root uses a **directory where you have full access**, maybe it could be useful to delete that folder and **create a symlink folder to another one** serving a script controlled by you
```bash
ln -d -s </PATH/TO/POINT> </PATH/CREATE/FOLDER>
```
### Frequent cron jobs
You can monitor the processes to search for processes that are being executed every 1,2 or 5 minutes. Maybe you can take advantage of it and escalate privileges.
For example, to **monitor every 0.1s during 1 minute**, **sort by less executed commands** and deleting the commands that have beeing executed all the time, you can do:
```bash
for i in $(seq 1 610); do ps -e --format cmd >> /tmp/monprocs.tmp; sleep 0.1; done; sort /tmp/monprocs.tmp | uniq -c | grep -v "\[" | sed '/^.\{200\}./d' | sort | grep -E -v "\s*[6-9][0-9][0-9]|\s*[0-9][0-9][0-9][0-9]"; rm /tmp/monprocs.tmp;
```
**You can also use** [**pspy**](https://github.com/DominicBreuker/pspy/releases) \(this will monitor and list every process that start\).
It's possible to create a cronjob **putting a carriage return after a comment** \(without new line character\), and the cron job will work. Example \(note the carriege return char\):
```bash
#This is a comment inside a cron config file\r* * * * * echo "Surprise!"
Check if you can write any `.service` file, if you can, you **could modify it** so it **executes** your **backdoor when** the service is **started**, **restarted** or **stopped** \(maybe you will need to wait until the machine is rebooted\).
For example create your backdoor inside the .service file with **`ExecStart=/tmp/script.sh`**
Keep in mid that if you have **write permissions over binaries being executed by services**, you can change them for backdoors so when the services get re-executed the backdoors will be executed.
### systemd PATH - Relative Paths
You can see the PATH used by **systemd** with:
```bash
systemctl show-environment
```
If you find that you can **write** in any of the folders of the path you may be able to **escalate privileges**. You need to search for **relative paths being used on service configurations** files like:
Then, create a **executable** with the **same name as the relative path binary** inside the systemd PATH folder you can write, and when the service is asked to execute the vulnerable action \(**Start**, **Stop**, **Reload**\), your **backdoor will be executed** \(unprivileged users usually cannot start/stop services but check if you can using `sudo -l`\).
**Timers** are systemd unit files whose name ends in . **timer** that control . service files or events. **Timers** can be used as an alternative to cron. **Timers** have built-in support for calendar time events, monotonic time events, and can be run asynchronously.
You can enumerate all the timers doing:
```bash
systemctl list-timers --all
```
### Writable timers
If you can modify a timer you can make it execute some existent systemd.unit \(like a `.service` or a `.target`\)
```bash
Unit=backdoor.service
```
In the documentation you can read what the Unit is:
> The unit to activate when this timer elapses. The argument is a unit name, whose suffix is not ".timer". If not specified, this value defaults to a service that has the same name as the timer unit, except for the suffix. \(See above.\) It is recommended that the unit name that is activated and the unit name of the timer unit are named identically, except for the suffix.
Therefore, in order to abuse this permissions you would need to:
* Find some systemd unit that is **executing a relative path** and you have **writable privileges** over the **systemd PATH** \(to impersonate that executable\)
Created symlink /etc/systemd/system/multi-user.target.wants/backu2.timer → /lib/systemd/system/backu2.timer.
```
Note the **timer** is **activated** by creating a symlink to it on `/etc/systemd/system/<WantedBy_section>.wants/<name>.timer`
## Sockets
In brief, a Unix Socket \(technically, the correct name is Unix domain socket, **UDS**\) allows **communication between two different processes** on either the same machine or different machines in client-server application frameworks. To be more precise, it’s a way of communicating among computers using a standard Unix descriptors file. \(From [here](https://www.linux.com/news/what-socket/)\).
*`ListenStream`, `ListenDatagram`, `ListenSequentialPacket`, `ListenFIFO`, `ListenSpecial`, `ListenNetlink`, `ListenMessageQueue`, `ListenUSBFunction`: This options are different but as summary as used to **indicate where is going to listen** the socket \(the path of the AF\_UNIX socket file, the IPv4/6 and/or port number to listen...\).
*`Accept`: Takes a boolean argument. If **true**, a **service instance is spawned for each incoming connection** and only the connection socket is passed to it. If **false**, all listening sockets themselves are **passed to the started service unit**, and only one service unit is spawned for all connections. This value is ignored for datagram sockets and FIFOs where a single service unit unconditionally handles all incoming traffic. **Defaults to false**. For performance reasons, it is recommended to write new daemons only in a way that is suitable for `Accept=no`.
*`ExecStartPre`, `ExecStartPost`: Takes one or more command lines, which are **executed before** or **after** the listening **sockets**/FIFOs are **created** and bound, respectively. The first token of the command line must be an absolute filename, then followed by arguments for the process.
*`ExecStopPre`, `ExecStopPost`: Additional **commands** that are **executed before** or **after** the listening **sockets**/FIFOs are **closed** and removed, respectively.
*`Service`: Specifies the **service** unit name **to activate** on **incoming traffic**. This setting is only allowed for sockets with Accept=no. It defaults to the service that bears the same name as the socket \(with the suffix replaced\). In most cases, it should not be necessary to use this option.
If you find a **writable**`.socket` file you can **add** at the begging of the `[Socket]` section something like: `ExecStartPre=/home/kali/sys/backdoor` and the backdoor will be executed before the socket is created. Therefore, you will **probably need to wait until the machine is rebooted.**
_Note that the system must be using that socket file configuration or the backdoor won't be executed_
### Writable sockets
If you **identify any writable socket** \(_now where are talking about Unix Sockets, not about the config `.socket` files_\), then, **you can communicate** with that socket and maybe exploit a vulnerability.
Note that there may be some **sockets listening for HTTP** requests \(_I'm not talking about .socket files but about the files acting as unix sockets_\). You can check this with:
#### Use docker web API from socket without docker package
If you have access to **docker socket** but you can't use the docker binary \(maybe it isn't even installed\), you can use directly the web API with `curl`.
The following commands are a example to **create a docker container that mount the root** of the host system and use `socat` to execute commands into the new docker.
Note that if you have write permissions over the docker socket because you are **inside the group `docker`** you have [**more ways to escalate privileges**](interesting-groups-linux-pe/#docker-group). If the [**docker API is listening in a port** you can also be able to compromise it](../../pentesting/2375-pentesting-docker.md#compromising).
D-BUS is an **inter-process communication \(IPC\) system**, providing a simple yet powerful mechanism **allowing applications to talk to one another**, communicate information and request services. D-BUS was designed from scratch to fulfil the needs of a modern Linux system.
D-BUS, as a full-featured IPC and object system, has several intended uses. First, D-BUS can perform basic application IPC, allowing one process to shuttle data to another—think **UNIX domain sockets on steroids**. Second, D-BUS can facilitate sending events, or signals, through the system, allowing different components in the system to communicate and ultimately to integrate better. For example, a Bluetooth dæmon can send an incoming call signal that your music player can intercept, muting the volume until the call ends. Finally, D-BUS implements a remote object system, letting one application request services and invoke methods from a different object—think CORBA without the complications. _\*\*_\(From [here](https://www.linuxjournal.com/article/7744)\).
D-Bus use an **allow/deny model**, where each message \(method call, signal emission, etc.\) can be **allowed or denied** according to the sum of all policy rules which match it. Each or rule in the policy should have the `own`, `send_destination` or `receive_sender` attribute set.
Therefore, if a policy is allowing your user in anyway to **interact with the bus**, you could be able to exploit it to escalate privileges \(maybe just listing for some passwords?\).
Note that a **policy** that **doesn't specify** any user or group affects everyone \(`<policy>`\).
Policies to the context "default" affects everyone not affected by other policies \(`<policy context="default"`\).
Check **who** you are, which **privileges** do you have, which **users** are in the systems, which ones can **login** and which ones have **root privileges:**
Some Linux versions were affected by a bug that allow users with **UID > INT\_MAX** to escalate privileges. More info: [here](https://gitlab.freedesktop.org/polkit/polkit/issues/74), [here](https://github.com/mirchr/security-research/blob/master/vulnerabilities/CVE-2018-19788.sh) and [here](https://twitter.com/paragonsec/status/1071152249529884674).
If you **know any password** of the environment **try to login as each user** using the password.
### Su Brute
If don't mind about doing a lot of noise and `su` and `timeout` binaries are present on the computer you can try to brute-force user using [su-bruteforce](https://github.com/carlospolop/su-bruteforce).
[**Linpeas**](https://github.com/carlospolop/privilege-escalation-awesome-scripts-suite) with `-a` parameter also try to brute-force users.
If you find that you can **write inside some folder of the $PATH** you may be able to escalate privileges by **creating a backdoor inside the writable folder** with the name of some command that is going to be executed by a different user \(root ideally\) and that is **not loaded from a folder that is located previous** to your writable folder in $PATH.
Sudo configuration might allow a user to execute some command with another user privileges without knowing the password.
```text
$ sudo -l
User demo may run the following commands on crashlab:
(root) NOPASSWD: /usr/bin/vim
```
In this example the user `demo` can run `vim` as `root`, it is now trivial to get a shell by adding an ssh key into the root directory or by calling `sh`.
This directive allows the user to **set an environment variable** while executing something:
```bash
$ sudo -l
User waldo may run the following commands on admirer:
(ALL) SETENV: /opt/scripts/admin_tasks.sh
```
This example, **based on HTB machine Admirer**, was **vulnerable** to **PYTHONPATH hijacking** in order to load an arbitrary python library while executing the script as root:
If the **sudo permission** is given to a single command **without specifying the path**: _hacker10 ALL= \(root\) less_ you can exploit it by changing the PATH variable
```bash
export PATH=/tmp:$PATH
#Put your backdoor in /tmp and name it "less"
sudo less
```
This technique can also be used if a **suid** binary **executes another command without specifying the path to it \(always check with**_**strings**_**the content of a weird SUID binary\)**.
[Payload examples to execute.](payloads-to-execute.md)
### SUID binary with command path
If the **suid** binary **executes another command specifying the path**, then, you can try to **export a function** named as the command that the suid file is calling.
For example, if a suid binary calls _**/usr/sbin/service apache2 start**_ you have to try to create the function and export it:
Then, when you call the suid binary, this function will be executed
### LD\_PRELOAD
**LD\_PRELOAD** is an optional environmental variable containing one or more paths to shared libraries, or shared objects, that the loader will load before any other shared library including the C runtime library \(libc.so\) This is called preloading a library.
To avoid this mechanism being used as an attack vector for _suid/sgid_ executable binaries, the loader ignores _LD\_PRELOAD_ if _ruid != euid_. For such binaries, only libraries in standard paths that are also _suid/sgid_ will be preloaded.
If you find inside the output of **`sudo -l`** the sentence: _**env\_keep+=LD\_PRELOAD**_ and you can call some command with sudo, you can escalate privileges.
sudo LD_PRELOAD=pe.so <COMMAND>#Use any command you can run with sudo
```
### SUID Binary – so injection
If you find some weird binary with **SUID** permissions, you could check if all the **.so** files are **loaded correctly**. In order to do so you can execute:
```bash
strace <SUID-BINARY> 2>&1 | grep -i -E "open|access|no such file"
```
For example, if you find something like: _pen\(“/home/user/.config/libcalc.so”, O\_RDONLY\) = -1 ENOENT \(No such file or directory\)_ you can exploit it.
Create the file _/home/user/.config/libcalc.c_ with the code:
[**GTFOBins**](https://gtfobins.github.io/) is a curated list of Unix binaries that can be exploited by an attacker to bypass local security restrictions.
The project collects legitimate functions of Unix binaries that can be abused to break out restricted shells, escalate or maintain elevated privileges, transfer files, spawn bind and reverse shells, and facilitate the other post-exploitation tasks.
If you can access `sudo -l` you can use the tool [**FallOfSudo**](https://github.com/Critical-Start/FallofSudo) to check if it finds how to exploit any sudo rule.
In the scenario where **you have a shell as a user with sudo privileges** but you don't know the password of the user, you can **wait him to execute some command using `sudo`**. Then, you can **access the token of the session where sudo was used and use it to execute anything as sudo** \(privilege escalation\).
Requirements to escalate privileges:
* You already have a shell as user "_sampleuser_"
* "_sampleuser_" have **used `sudo`** to execute something in the **last 15mins** \(by default that's the duration of the sudo token that allows to use `sudo` without introducing any password\)
*`cat /proc/sys/kernel/yama/ptrace_scope` is 0
*`gdb` is accessible \(you can be able to upload it\)
\(You can temporarily enable `ptrace_scope` with `echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope` or permanently modifying `/etc/sysctl.d/10-ptrace.conf` and setting `kernel.yama.ptrace_scope = 0`\)
If all these requirements are met, **you can escalate privileges using:** [**https://github.com/nongiach/sudo\_inject**](https://github.com/nongiach/sudo_inject)
* The **first exploit** \(`exploit.sh`\) will create the binary `activate_sudo_token` in _/tmp_. You can use it to **activate the sudo token in your session** \(you won't get automatically a root shell, do `sudo su`\):
* The **second exploit** \(`exploit_v2.sh`\) will create a sh shell in _/tmp_**owned by root with setuid**
```bash
bash exploit_v2.sh
/tmp/sh -p
```
* The **third exploit** \(`exploit_v3.sh`\) will **create a sudoers file** that makes **sudo tokens eternal and allows all users to use sudo**
```bash
bash exploit_v3.sh
sudo su
```
### /var/run/sudo/ts/<Username>
If you have **write permissions** in the folder or on any of the created files inside the folder you can use the binary [**write\_sudo\_token**](https://github.com/nongiach/sudo_inject/tree/master/extra_tools) to **create a sudo token for a user and PID**.
For example if you can overwrite the file _/var/run/sudo/ts/sampleuser_ and you have a shell as that user with PID 1234, you can **obtain sudo privileges** without needing to know the password doing:
The file `/etc/sudoers` and the files inside `/etc/sudoers.d` configure who can use `sudo` and how. This files **by default can only be read by user root and group root**.
**If** you can **read** this file you could be able to **obtain some interesting information**, and if you can **write** any file you will be able to **escalate privileges**.
The file `/etc/ld.so.conf` indicates **where are loaded the configurations files from**. Typically, this file contains the following path: `include /etc/ld.so.conf.d/*.conf`
That means that the configuration files from `/etc/ld.so.conf.d/*.conf` will be read. This configuration files **points to another folders** where **libraries** are going to be **searched** for. For example, the content of `/etc/ld.so.conf.d/libc.conf` is `/usr/local/lib`. **This means that the system will search for libraries inside `/usr/local/lib`**.
If for some reason **a user has write permissions** on any of the paths indicated: `/etc/ld.so.conf`, `/etc/ld.so.conf.d/`, any file inside `/etc/ld.so.conf.d/` or any folder indicated inside any config file inside `/etc/ld.so.conf.d/*.conf` he may be able to escalate privileges.
Take a look about **how to exploit this misconfiguration** in the following page:
Linux capabilities provide a **subset of the available root privileges to a process**. This effectively breaks up root **privileges into smaller and distinctive units**. Each of these units can then be independently be granted to processes. This way the full set of privileges is reduced and decreasing the risks of exploitation.
ACLs are a second level of discretionary permissions, that **may override the standard ugo/rwx** ones. When used correctly they can grant you a **better granularity in setting access to a file or a directory**, for example by giving or denying access to a specific user that is neither the file owner, nor in the group owner \(from [**here**](https://linuxconfig.org/how-to-manage-acls-on-linux)\).
**Give** user "kali" read and write permissions over a file:
In **old versions** you may **hijack** some **shell** session of a different user \(**root**\).
In **newest versions** you will be able to **connect** to screen sessions only of **your own user**. However, you could find **interesting information inside of the session**.
All SSL and SSH keys generated on Debian-based systems \(Ubuntu, Kubuntu, etc\) between September 2006 and May 13th, 2008 may be affected by this bug.
This bug caused that when creating in those OS a new ssh key **only 32,768 variations were possible**. This means that all the possibilities can be calculated and **having the ssh public key you can search for the corresponding private key**. You can find the calculated possibilities here: [https://github.com/g0tmi1k/debian-ssh](https://github.com/g0tmi1k/debian-ssh)
### SSH Interesting configuration values
* **PasswordAuthentication:** Specifies whether password authentication is allowed. The default is `no`.
* **PubkeyAuthentication:** Specifies whether public key authentication is allowed. The default is `yes`.
* **PermitEmptyPasswords**: When password authentication is allowed, it specifies whether the server allows login to accounts with empty password strings. The default is `no`.
#### PermitRootLogin
Specifies whether root can log in using ssh, default is `no`. Possible values:
*`yes` : root can login using password and private key
*`without-password` or `prohibit-password`: root can only login with private key
*`forced-commands-only`: Root can login only using privatekey cand if the commands options is specified
*`no` : no
#### AuthorizedKeysFile
Specifies files that contains the public keys that can be used for user authentication. I can contains tokens like `%h` , that will be replaced by the home directory. **You can indicate absolute paths** \(starting in `/`\) or **relative paths from the users home**. For example:
That configuration will indicate that if you try to login with the **private** key **\*\*of the user "**testusername\*\*" ssh is going to compare the public key of your key with the ones located in `/home/testusername/.ssh/authorized_keys` and `/home/testusername/access`
SSH agent forwarding allows you to **use your local SSH keys instead of leaving keys** \(without passphrases!\) sitting on your server. So, you will be able to **jump** via ssh **to a host** and from there **jump to another** host **using** the **key** located in your **initial host**.
You need to set this option in `$HOME/.ssh.config` like this:
```text
Host example.com
ForwardAgent yes
```
Notice that if `Host` is `*` every time the user jumps to a different machine that host will be able to access the keys \(which is a security issue\).
The file `/etc/ssh_config` can **override** this **options** and allow or denied this configuration.
The file `/etc/sshd_config` can **allow** or **denied** ssh-agent forwarding with the keyword `AllowAgentForwarding` \(default is allow\).
If you Forward Agent configured in an environment **\*\*\[**check here how to exploit it to escalate privileges\*\*\]\(ssh-forward-agent-exploitation.md\).
The file `/etc/profile` and the files under `/etc/profile.d/` are **scripts that are executed when a user run a new shell**. Therefore, if you can **write or modify any of the you can escalate privileges**.
Depending on the OS the `/etc/passwd` and `/etc/shadow` files may be using a different name or there may be a backup. Therefore it's recommended **find all of hem** and **check if you can read** them and **check if there are hashes** inside the files:
You should check if you can **write in some sensitive file**. For example, can you write to some **service configuration file**?
```bash
find / '(' -type f -or -type d ')' '(' '(' -user $USER ')' -or '(' -perm -o=w ')' ')' 2>/dev/null | grep -v '/proc/' | grep -v $HOME | sort | uniq #Find files owned by the user or writable by anybody
for g in `groups`; do find \( -type f -or -type d \) -group $g -perm -g=w 2>/dev/null | grep -v '/proc/' | grep -v $HOME; done #Find files writable by any group of the user
```
For example, if the machine is running a **tomcat** server and you can **modify the Tomcat service configuration file inside /etc/systemd/,** then you can modify the lines:
```text
ExecStart=/path/to/backdoor
User=root
Group=root
```
Your backdoor will be executed the next time that tomcat is started.
The following folders may contain backups or interesting information: **/tmp**, **/var/tmp**, **/var/backups, /var/mail, /var/spool/mail, /etc/exports, /root** \(Probably you won't be able to read the last one but try\)
```bash
ls -a /tmp /var/tmp /var/backups /var/mail/ /var/spool/mail/ /root
```
### Weird Location/Owned files
```bash
#root owned files in /home folders
find /home -user root 2>/dev/null
#Files owned by other users in folders owned by me
for d in `find /var /etc /home /root /tmp /usr /opt /boot /sys -type d -user $(whoami) 2>/dev/null`; do find $d ! -user `whoami` -exec ls -l {} \; 2>/dev/null; done
#Files owned by root, readable by me but no world readable
find / -type f -user root ! -perm -o=r 2>/dev/null
Read the code of [**linPEAS**](https://github.com/carlospolop/privilege-escalation-awesome-scripts-suite/tree/master/linPEAS), it searches for **several possible files that could contain passwords**.
**Other interesting tool** that you can use to do so is: [**LaZagne**](https://github.com/AlessandroZ/LaZagne) which is an open source application used to retrieve lots of passwords stored on a local computer for Windows, Linux & Mac.
If you can read logs, you may be able to find **interesting/confidential information inside of them**. The more strange the log is, the more interesting will be \(probably\).
Also, some "**bad**" configured \(backdoored?\) **audit logs** may allow you to **record passwords** inside audit logs as explained in this post: [https://www.redsiege.com/blog/2019/05/logging-passwords-on-linux/](https://www.redsiege.com/blog/2019/05/logging-passwords-on-linux/).
You should also check for files containing the word "**password**" in it's **name** or inside the **content**, also check for IPs and emails inside logs, or hashes regexps.
I'm not going to list here how to do all of this but if you are interested you can check the last checks that [**linpeas**](https://github.com/carlospolop/privilege-escalation-awesome-scripts-suite/blob/master/linPEAS/linpeas.sh) perform.
If you know from **where** a python script is going to be executed and you **can write inside** that folder or you can **modify python libraries**, you can modify the os library and backdoor it \(if you can write where python script is going to be executed, copy and paste the os.py library\).
To **backdoor the library** just add at the end of the os.py library the following line \(change IP and PORT\):
There is a vulnerability on `logrotate`that allows a user with **write permissions over a log file** or **any** of its **parent directories** to make `logrotate`write **a file in any location**. If **logrotate** is being executed by **root**, then the user will be able to write any file in _**/etc/bash\_completion.d/**_ that will be executed by any user that login.
So, if you have **write perms** over a **log file****or** any of its **parent folder**, you can **privesc** \(on most linux distributions, logrotate is executed automatically once a day as **user root**\). Also, check if apart of _/var/log_ there are more files being **rotated**.
This vulnerability affects `logrotate` version `3.15.1` and below
{% endhint %}
More detailed information about the vulnerability can be found in this page: [https://tech.feedyourhead.at/content/details-of-a-logrotate-race-condition](https://tech.feedyourhead.at/content/details-of-a-logrotate-race-condition).
You can exploit this vulnerability with [**logrotten**](https://github.com/whotwagner/logrotten).
This vulnerability is very similar to [**CVE-2016-1247**](https://www.cvedetails.com/cve/CVE-2016-1247/) **\(nginx logs\),** so whenever you find that you can alter logs, check who is managing those logs and check if you can escalate privileges substituting the logs by symlinks.
If, for whatever reason, a user is able to **write** an `ifcf-<whatever>` script to _/etc/sysconfig/network-scripts_**or** it can **adjust** an existing one, then your **system is pwned**.
Network scripts, _ifcg-eth0_ for example are used for network connections. The look exactly like .INI files. However, they are ~sourced~ on Linux by Network Manager \(dispatcher.d\).
In my case, the `NAME=` attributed in these network scripts is not handled correctly. If you have **white/blank space in the name the system tries to execute the part after the white/blank space**. Which means; **everything after the first blank space is executed as root**.
For example: _/etc/sysconfig/network-scripts/ifcfg-1337_
```bash
NAME=Network /bin/id
ONBOOT=yes
DEVICE=eth0
```
\(_Note the black space between Network and /bin/id_\)
`/etc/init.d` contains **scripts** used by the System V init tools \(SysVinit\). This is the **traditional service management package for Linux**, containing the `init` program \(the first process that is run when the kernel has finished initializing¹\) as well as some infrastructure to start and stop services and configure them. Specifically, files in `/etc/init.d` are shell scripts that respond to `start`, `stop`, `restart`, and \(when supported\) `reload` commands to manage a particular service. These scripts can be invoked directly or \(most commonly\) via some other trigger \(typically the presence of a symbolic link in `/etc/rc?.d/`\). \(From [here](https://askubuntu.com/questions/5039/what-is-the-difference-between-etc-init-and-etc-init-d#:~:text=%2Fetc%2Finit%20contains%20configuration%20files,the%20status%20of%20a%20service.)\)
Other alternative to this folder is `/etc/rc.d/init.d` in Redhat
`/etc/init` contains **configuration** files used by **Upstart**. Upstart is a young **service management package** championed by Ubuntu. Files in `/etc/init` are configuration files telling Upstart how and when to `start`, `stop`, `reload` the configuration, or query the `status` of a service. As of lucid, Ubuntu is transitioning from SysVinit to Upstart, which explains why many services come with SysVinit scripts even though Upstart configuration files are preferred. In fact, the SysVinit scripts are processed by a compatibility layer in Upstart. \(From [here](https://askubuntu.com/questions/5039/what-is-the-difference-between-etc-init-and-etc-init-d#:~:text=%2Fetc%2Finit%20contains%20configuration%20files,the%20status%20of%20a%20service.)\)
**systemd** is a **Linux initialization system and service manager that includes features like on-demand starting of daemons**, mount and automount point maintenance, snapshot support, and processes tracking using Linux control groups. systemd provides a logging daemon and other tools and utilities to help with common system administration tasks. \(From [here](https://www.linode.com/docs/quick-answers/linux-essentials/what-is-systemd/#:~:text=The%20%2Frun%2Fsystemd%2Fsystem,anywhere%20else%20in%20the%20system.)\)
Files that ships in packages downloaded from distribution repository go into `/usr/lib/systemd/`. Modifications done by system administrator \(user\) go into `/etc/systemd/system/`.
#### **Best tool to look for Linux local privilege escalation vectors:** [**LinPEAS**](https://github.com/carlospolop/privilege-escalation-awesome-scripts-suite/tree/master/linPEAS)
**Recopilation of more scripts**: [https://gh-dark.rauchg.now.sh/1N3/PrivEsc/tree/master/linux](https://gh-dark.rauchg.now.sh/1N3/PrivEsc/tree/master/linux)
