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
History

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2021-01-15T20:10:31

Updated: 2024-08-03T18:09:15.155Z

Reserved: 2020-12-22T00:00:00

Link: CVE-2021-21249

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2021-01-15T21:15:13.740

Modified: 2022-04-26T16:13:44.967

Link: CVE-2021-21249

cve-icon Redhat

No data.