CVE-2021-21249
In OneDev before version 4.0.3, there is an issue involving YAML parsing which can lead to post-auth remote code execution.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.06%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 3.06% probability · 88th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-74, CWE-502
- Affected
- onedev project/onedev
- Source
- security-advisories@github.com
EPSS 3.1% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66Patch, Third Party Advisory
- https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpmThird Party Advisory
- https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66Patch, Third Party Advisory
- https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpmThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.