CVE intelligence and bounded remediation

CVE-2021-21247 — OneDev is an all-in-one devops platform

Critical CVSS 9.6

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.

Severity
Critical
CVSS
9.6 (3.1)
Published
2021-01-15
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-74, CWE-502

Affected products

  • onedev_project / onedev

Matched remediation archetype

Unsafe deserialization and object reconstruction

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Check exposure

  • Inventory serialization formats accepted from requests, queues, caches, files, cookies, and cross-service messages.
  • Trace whether untrusted input can select classes, types, callbacks, constructors, or object hooks during decoding.
  • Identify signing, schema validation, trust-boundary, and compatibility settings for each decoder.

Remediate safely

  • Replace native object deserialization with a data-only format and explicit schema validation.
  • If replacement is not immediate, use a safe decoder with a minimal type allowlist and disable polymorphic or executable hooks.
  • Update the affected library and add inert tests for unknown types, extra fields, malformed nesting, and unsigned data.

Authoritative sources

Complete CVE record and remediation plan

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