What’s Vulnerable › Vulnerabilities

CVE-2021-21247: Post-Auth Unsafe Deserialization on BasePage (AJAX)

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-01-15 · updated 2026-06-17
• Weakness: CWE-74

Description

OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, the application's BasePage registers an AJAX event listener (`AbstractPostAjaxBehavior`) in all pages other than the login page. This listener decodes and deserializes the `data` query parameter. We can access this listener by submitting a POST request to any page. This issue may lead to `post-auth RCE` This endpoint is subject to authentication and, therefore, requires a valid user to carry on the attack. This issue was addressed in 4.0.3 by encrypting serialization payload with secrets only known to server.

Affected products

• theonedev onedev: before 4.0.3 — fixed in 4.0.3

How to fix

Upgrade to a fixed version: theonedev onedev 4.0.3. Check the vendor advisory for mitigations.

References

• https://github.com/theonedev/onedev/security/advisories/GHSA-6pxf-75cf-vwjp
• https://github.com/theonedev/onedev/security/advisories/GHSA-6pxf-75cf-vwjp

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