CVE-2021-21249 | BDVDB-2026-147661 Detail

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

Impact#

Weaknesses#

References#

Exploit#

History#

1. Version 12021-01-15Record published in the CVE List.
2. Version 22024-08-03Most recent update recorded in the CVE List.