CVE-2021-21249

 

Published at: - 15-01-2021 10:15

Last modified: - 26-04-2022 06:13

Total changes: - 4

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

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

 

Verification logic

 

Reference

• https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpm
• https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66

 

Keywords

NVD

 

CVE-2021-21249

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures