What is CVE-2021-21243?

CVE-2021-21243 is a critical-severity vulnerability in Onedev Project, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 10.0/10. Published 2021-01-15.

How severe is CVE-2021-21243?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Deserialization in Onedev Project

CVE-2021-21243

OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, a Kubernetes REST endpoint exposes two methods that deserialize untrusted data from the request body. These endpoints do not enforce any authentication or authorization checks. This issue may lead to pre-auth RCE. This issue was fixed in 4.0.3 by not using deserialization at KubernetesResource side.

Published 2021-01-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.545 (99.0th percentile), scored 2026-10-20.

High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.545 · newest: 0.545 · change: 0.000

Affected products

Onedev Project
Theonedev Onedev — versions < 4.0.3

Weakness classification (CWE)

References

github.com/theonedev/onedev/security/advisories/GHSA-9mmq-fm8c-q4fv (Third Party Advisory)
github.com/theonedev/onedev/commit/9637fc8fa461c5777282a0021c3deb1e7a48f137 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-21243?: CVE-2021-21243 is a critical-severity vulnerability in Onedev Project, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 10.0/10. Published 2021-01-15.
How severe is CVE-2021-21243?: Critical severity. CVSS v3 base score is 10.0 out of 10.