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Case File

CVE-2021-21251

HIGH · CVSS 7.7 EPSS 12.16% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-01-15 · Last synced 2026-08-04

CyberRota Analysis

This is a high severity vulnerability with a CVSS score of 7.7. It affects Apache, Kubernetes. Public exploit code or proof-of-concept references have been detected in its references. Its EPSS score suggests a 12.2% probability of exploitation in the next 30 days.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit
GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-21251
Severity
HIGH
CVSS
7.7
EPSS
12.16%
Apache Kubernetes

Original NVD Description

OneDev is an all-in-one devops platform. In OneDev before version 4.0.3 there is a critical "zip slip" vulnerability. This issue may lead to arbitrary file write. The KubernetesResource REST endpoint untars user controlled data from the request body using TarUtils. TarUtils is a custom library method leveraging Apache Commons Compress. During the untar process, there are no checks in place to prevent an untarred file from traversing the file system and overriding an existing file. For a successful exploitation, the attacker requires a valid __JobToken__ which may not be possible to get without using any of the other reported vulnerabilities. But this should be considered a vulnerability in `io.onedev.commons.utils.TarUtils` since it lives in a different artifact and can affect other projects using it. This issue was addressed in 4.0.3 by validating paths in tar archive to only allow them to be in specified folder when extracted.

Related CVEs

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