CVE-2021-21249
9.6 · CRITICALOverview
CVE-2021-21249 is a critical-severity vulnerability affecting onedev_project onedev. It was published on January 15, 2021 and has a CVSS 3.1 base score of 9.6 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.6, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical 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
Remediation
Check the references section for vendor advisories and patches from onedev_project. Update onedev to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| onedev_project | onedev | >= 0, < 4.0.3 | Affected |
References
Frequently Asked Questions
What is CVE-2021-21249?
CVE-2021-21249 is a critical-severity vulnerability affecting onedev_project onedev. It was published on January 15, 2021 and has a CVSS 3.1 base score of 9.6 (CRITICAL).
How severe is CVE-2021-21249?
This vulnerability has a CVSS 3.1 base score of 9.6, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-21249?
Check the references section for vendor advisories and patches from onedev_project. Update onedev to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-21249?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-21249 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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