CVE-2021-29472: Missing argument delimiter can lead to code execution via VCS repository URLs or source download URLs on systems with Mercurial in composer
Noroxi assessment
Priority: Monitor (action score 36/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 4.7% (FIRST EPSS); higher than 91.9% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: composer (Alpine:v3.13) 2.0.13-r0; composer (Debian:10) 1.8.4-1+deb10u1; composer (Debian:12) 2.0.9-2.
- Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to composer (Alpine:v3.13) 2.0.13-r0; composer (Debian:10) 1.8.4-1+deb10u1; composer (Debian:12) 2.0.9-2 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Apr 27, 2021
- Updated
- Jun 16, 2026
- EPSS
- 4.7% · 91th percentile
- CWE
- CWE-88
Report tools
Action score
36
Monitor
Low priority for now.
- CVSS
- 35 / 40 · 8.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 4.7%
CNA vs NVD score
- NVD
- 8.8
- CNA · GitHub_M
- 8.8
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| getcomposer | composer | cpe:2.3:a:getcomposer:composer |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux10.0
- debian debian linux9.0
- fedoraproject fedora33
- fedoraproject fedora34
- getcomposer composerbefore 1.10.22
- getcomposer composer2.0 and later · before 2.0.13
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
composer composer
- < 1.10.22, >=2.0,<2.0.13affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.13 | composer | from 2.0 · before 2.0.13-r0 | 2.0.13-r0 |
| Debian:10 | composer | before 1.8.4-1+deb10u1 | 1.8.4-1+deb10u1 |
| Debian:12 | composer | before 2.0.9-2 | 2.0.9-2 |
| Debian:9 | composer | before 1.2.2-1+deb9u1 | 1.2.2-1+deb9u1 |
| openSUSE:Leap 15.2 | php-composer | before 1.10.22-bp153.2.3.1 | 1.10.22-bp153.2.3.1 |
| openSUSE:Tumbleweed | php-composer | before 1.10.22-2.2 | 1.10.22-2.2 |
| Packagist | composer/composer | from 2.0.0-alpha1 · before 2.0.13 | 2.0.13 |
| Packagist | composer/composer | before 1.10.22 | 1.10.22 |
| SUSE:Package Hub 15 SP1 | php-composer | before 1.10.22-bp153.2.3.1 | 1.10.22-bp153.2.3.1 |
Same product
getcomposer: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-41116Command injection in composer on Windows40Plan
- CVE-2026-40261Composer has Command Injection via Malicious Perforce Reference36Monitor
- CVE-2022-24828Missing input validation can lead to command execution in composer36Monitor
Published before and after this one in the same product
- Later →CVE-2015-8371Sep 21, 2023 · Composer before 2016-02-10 allows cache poisoning from other projects built on the same host.35Monitor
- Later →CVE-2023-43655Sep 29, 2023 · Remote Code Execution via web-accessible composer.phar35Monitor
- Later →CVE-2024-24821Feb 8, 2024 · Code execution and possible privilege escalation via compromised InstalledVersions.php or installed.php in Composer31Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:composer | 2.0.13-r0 · Alpine:v3.13 | Package registry (OSV) |
| debian:composer | 2.0.9-2 · Debian:12 | Package registry (OSV) |
| opensuse:php-composer | 1.10.22-bp153.2.3.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| Packagist:composer/composer | 1.10.22 | Package registry (OSV) |
| Packagist:composer/composer | 2.0.13 | Package registry (OSV) |
| suse:php-composer | 1.10.22-bp153.2.3.1 · SUSE:Package Hub 15 SP1 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-21-0764 · Sep 22, 2021(SUSE Linux Enterprise Güncellemesi)
- TR-21-0378 · May 4, 2021(Debian Güvenlik Güncellemesi Yayınladı)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-88 · Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Parameter InjectionCAPEC-137likelihood: Medium · Medium
- Flash Parameter InjectionCAPEC-174likelihood: High · Medium
- Using Meta-characters in E-mail Headers to Inject Malicious PayloadsCAPEC-41likelihood: High · High
- HTTP Parameter Pollution (HPP)CAPEC-460Medium
- OS Command InjectionCAPEC-88likelihood: High · High
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- github.com/composer/composer/security/advisories/GHSA-h5h8-pc6h-jvvx
- lists.debian.org/debian-lts-announce/2021/05/msg00009.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FAQUAMGO4Q4BLNZ2OH4CXQD7UK4IO2GE/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KN3DMFH42BJW45VT6FYF2RXKC26D6VC2/
- www.debian.org/security/2021/dsa-4907
Vendor advisories and official records. Exploit/PoC links are deliberately left out.