CVE-2021-22864 - CVE House

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Status published High CVE-2021-22864

Unsafe configuration options in GitHub Pages leading to remote code execution on GitHub Enterprise Server

8.8 CVSS

Vulnerability Description

A remote code execution vulnerability was identified in GitHub Enterprise Server that could be exploited when building a GitHub Pages site. User-controlled configuration options used by GitHub Pages were not sufficiently restricted and made it possible to override environment variables leading to code execution on the GitHub Enterprise Server instance. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.0.3 and was fixed in 3.0.3, 2.22.9, and 2.21.17. This vulnerability was reported via the GitHub Bug Bounty program.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

yvvdwf

References

More from GitHub

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Incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed read-only access

Incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed unauthorized read-only access

GitHub Enterprise Server Information Disclosure Vulnerability Exposes Private Repository Names via Search API

Pre-Receive Hook Remote Code Execution vulnerability was identified in GitHub Enterprise Server that allowing Privilege Escalation

Markdown math block sanitization bypass allows privilege escalation and unauthorized workflow triggers

Affected Vendor

GitHub

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Affected Software

GitHub Enterprise Server

Vulnerable Versions:

2.21, 2.22, 3.0

Timeline

Official Publish: March 23rd, 2021

Last Modified: August 3rd, 2024

Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weaknesses (CWE)

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application

T1059 Command and Scripting Interpreter

T1068 Exploitation for Privilege Escalation

Privilege Escalation

T1105 Ingress Tool Transfer

Command and Control