# CVE-2021-29472: Composer's missing argument delimiter can lead to code execution via VCS repository URLs or source download URLs on systems with Mercurial > Attackers can execute arbitrary code via crafted Mercurial URLs in Composer, primarily affecting services like Packagist that process user-supplied inputs. - **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 27 Apr 2021 - **Updated:** 3 Aug 2024 - **Also known as:** BIT-composer-2021-29472, CLEANSTART-2024-XJ18859, DEBIAN-CVE-2021-29472, DLA-2654-1, DSA-4907-1, GHSA-h5h8-pc6h-jvvx, UBUNTU-CVE-2021-29472, USN-5220-1, openSUSE-SU-2021:1289-1, openSUSE-SU-2024:11166-1 ## What is CVE-2021-29472? CVE-2021-29472 is a high-severity command injection vulnerability in Debian Debian Linux, published on 27 Apr 2021. Any signed-in user can exploit it over the network, with no action from the victim. ### Official 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. Weakness: CWE-94 (Improper Control of Generation of Code), CWE-88 (Improper Neutralization of Argument Delimiters in a Command) ## Which versions are affected by CVE-2021-29472? 5 open source packages ship an affected version, including composer/composer and composer. It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `composer/composer` | Packagist | All versions | 1.10.22 | | `composer/composer` | Packagist | All versions | 1.10.22 | | `composer/composer` | Packagist | From 2.0.0-alpha1 | 2.0.13 | | `composer/composer` | Packagist | From 2.0.0-alpha1 | 2.0.13 | | `composer` | Bitnami | All versions | 1.10.22, 2.0.13 | | `php-composer` | SUSE:Package Hub 15 SP1 | All versions | 1.10.22-bp153.2.3.1 | | `php-composer` | SUSE:Package Hub 15 SP2 | All versions | 1.10.22-bp153.2.3.1 | | `php-composer` | SUSE:Package Hub 15 SP3 | All versions | 1.10.22-bp153.2.3.1 | | `php-composer` | openSUSE:Leap 15.2 | All versions | 1.10.22-bp153.2.3.1 | | `php-composer` | openSUSE:Leap 15.3 | All versions | 1.10.22-bp153.2.3.1 | | `php-composer` | openSUSE:Tumbleweed | All versions | 1.10.22-2.2 | Products: Debian Debian Linux, Fedoraproject Fedora, Getcomposer Composer. ## How do I fix CVE-2021-29472? Upgrade composer/composer to a fixed version for your release line: 1.10.22 or 2.0.13. ## Is CVE-2021-29472 being exploited? There is no known exploitation of CVE-2021-29472 in the wild and no public exploit code. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-29472 and fix it if it is affected. What it is: CVE-2021-29472 is a high-severity command injection vulnerability in Debian Debian Linux, published on 27 Apr 2021. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2021-29472 in the wild and no public exploit code. Affected packages and fixed versions: - composer/composer (Packagist): affected all versions; fixed in 1.10.22 - composer/composer (Packagist): affected all versions; fixed in 1.10.22 - composer/composer (Packagist): affected from 2.0.0-alpha1; fixed in 2.0.13 - composer/composer (Packagist): affected from 2.0.0-alpha1; fixed in 2.0.13 - composer (Bitnami): affected all versions; fixed in 1.10.22, 2.0.13 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2021-29472/ (Markdown: https://insights.sbomify.com/CVE-2021-29472/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29472 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29472 - OSV: https://osv.dev/vulnerability/CVE-2021-29472 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-29472/ Summaries are generated and may contain mistakes; the official description above is the record.