CVE-2021-21249

Summary

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

Affected Software

VendorProductVersion RangeStatus
theonedevonedev< 4.0.3affected

Weaknesses

  • CWE-74: CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

ADP Enrichment

CVE Program Container

Additional References

References