CVE-2021-21249

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 v3.0 8.8 HIGH
CVSS v2.0 6.5 MEDIUM

8.8^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

6.5^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:S/C:P/I:P/A:P

Exploitability : 8.0 / Impact : 6.4

Access Vector NETWORK

Access Complexity LOW

Authentication SINGLE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpm	Third Party Advisory
https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66	Patch Third Party Advisory

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Configurations

Configuration 1 (hide)

cpe:2.3:a:onedev_project:onedev:*:*:*:*:*:*:*:*

Information

Published : 2021-01-15 13:15

Updated : 2022-04-26 09:13

NVD link : CVE-2021-21249

Mitre link : CVE-2021-21249

JSON object : View

CWE

CWE-502

Deserialization of Untrusted Data

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Products Affected

onedev_project

onedev

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