Vulnerability Description
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is an issue involving YAML parsing which can lead to post-auth remote code execution. In order to parse and process YAML files, OneDev uses SnakeYaml which by default (when not using `SafeConstructor`) allows the instantiation of arbitrary classes. We can leverage that to run arbitrary code by instantiating classes such as `javax.script.ScriptEngineManager` and using `URLClassLoader` to load the script engine provider, resulting in the instantiation of a user controlled class. For a full example refer to the referenced GHSA. This issue was addressed in 4.0.3 by only allowing certain known classes to be deserialized
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Onedev Project | Onedev | < 4.0.3 |
Related Weaknesses (CWE)
References
- https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8PatchThird Party Advisory
- https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpmThird Party Advisory
- https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8PatchThird Party Advisory
- https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpmThird Party Advisory
FAQ
What is CVE-2021-21249?
CVE-2021-21249 is a vulnerability with a CVSS score of 9.6 (CRITICAL). OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is an issue involving YAML parsing which can lead to post-auth remote code execution. In order to parse and process YAML ...
How severe is CVE-2021-21249?
CVE-2021-21249 has been rated CRITICAL with a CVSS base score of 9.6/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2021-21249?
Check the references section above for vendor advisories and patch information. Affected products include: Onedev Project Onedev.