CVE-2021-29472

HIGH
Published Apr 27, 20215y ago · Modified Jun 17, 20262w ago
8.8 CVSS 3.1
High
Find Similar
Published Apr 27, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

Description

Composer is a dependency manager for PHP. URLs for Mercurial repositories in the root composer.json and package source download URLs are not sanitized correctly. Specifically crafted URL values allow code to be executed in the HgDriver if hg/Mercurial is installed on the system. The impact to Composer users directly is limited as the composer.json file is typically under their own control and source download URLs can only be supplied by third party Composer repositories they explicitly trust to download and execute source code from, e.g. Composer plugins. The main impact is to services passing user input to Composer, including Packagist.org and Private Packagist. This allowed users to trigger remote code execution. The vulnerability has been patched on Packagist.org and Private Packagist within 12h of receiving the initial vulnerability report and based on a review of logs, to the best of our knowledge, was not abused by anyone. Other services/tools using VcsRepository/VcsDriver or derivatives may also be vulnerable and should upgrade their composer/composer dependency immediately. Versions 1.10.22 and 2.0.13 include patches for this issue.

CVSS Details

Base Score
8.8
Exploitability
2.8
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 2

CWE-88
CWE-94 Improper Control of Generation of Code (Code Injection) Injection

Affected Products 6

VendorProductVersionRange
getcomposercomposer* <1.10.22
getcomposercomposer*≥2.0  –  <2.0.13
debiandebian_linux9.0any
debiandebian_linux10.0any
fedoraprojectfedora33any
fedoraprojectfedora34any

References 7

  • blog.sonarsource.com https://blog.sonarsource.com/php-supply-chain-attack-on-composer/
    ExploitThird Party Advisory
  • getcomposer.org https://getcomposer.org/
    Vendor Advisory
  • github.com https://github.com/composer/composer/security/advisories/GHSA-h5h8-pc6h-jvvx
    Third Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2021/05/msg00009.html
    Mailing ListThird Party Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FAQUAMGO4Q4BLNZ2OH4CXQD7UK4IO2GE/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KN3DMFH42BJW45VT6FYF2RXKC26D6VC2/
  • debian.org https://www.debian.org/security/2021/dsa-4907
    Third Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.