Vulnerability in OneDev is an all-in-one devops platform. In… (CVE-2021-21249)

Summary

Vulnerability in OneDev is an all-in-one devops platform. In OneDev (CVE-2021-21249). Successful exploitation can lead to full system takeover. Exploitable via SafeConstructor.

Original description

The description as published by the source.

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

Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2021-21249 has been found in OneDev is an all-in-one devops platform. In OneDev.
Attackers can target a specific entry point like SafeConstructor over the network to misuse the product.
Successful exploitation can lead to full system takeover.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "OneDev is an all-in-one devops platform. In OneDev CVE-2021-21249" on the vendor's site.

CVE-2021-21249 (OneDev is an all-in-one devops platform. In OneDev)
Attack vector: remote (network-reachable) / no user interaction
Attack surface: SafeConstructor / javax.script.ScriptEngineManager / URLClassLoader
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in OneDev is an all-in-one devops platform. In OneDev. Attackers reach the vulnerable code path via SafeConstructor.

📍 Affected scope

Check the vendor advisory for the affected versions of OneDev is an all-in-one devops platform. In OneDev. Attack surface: SafeConstructor / javax.script.ScriptEngineManager / URLClassLoader.

🔥 Severity

Severity: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで OneDev is an all-in-one devops platform. In OneDev を使っているサービスとバージョンを洗い出す。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

References

advisory github.com
patch github.com