# CVE-2023-43655: Remote Code Execution via web-accessible composer.phar

> Remote code execution is possible if composer.phar is web-accessible and PHP register_argc_argv is enabled, requiring upgrades or configuration changes.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 29 Sep 2023
- **Updated:** 18 Jun 2025
- **Also known as:** BIT-composer-2023-43655, CLEANSTART-2024-OM41616, DEBIAN-CVE-2023-43655, DLA-3777-1, GHSA-jm6m-4632-36hf, SUSE-SU-2023:4041-1, UBUNTU-CVE-2023-43655, openSUSE-SU-2024:13290-1

## What is CVE-2023-43655?

CVE-2023-43655 is a medium-severity code injection vulnerability in Debian Debian Linux, published on 29 Sep 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Composer is a dependency manager for PHP. Users publishing a composer.phar to a public web-accessible server where the composer.phar can be executed as a php file may be subject to a remote code execution vulnerability if PHP also has `register_argc_argv` enabled in php.ini. Versions 2.6.4, 2.2.22 and 1.10.27 patch this vulnerability. Users are advised to upgrade. Users unable to upgrade should make sure `register_argc_argv` is disabled in php.ini, and avoid publishing composer.phar to the web as this is not best practice.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2023-43655?

7 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 | 1.10.27 |
| `composer/composer` | Packagist | All versions | 1.10.27 |
| `composer/composer` | Packagist | From 2.0.0 | 2.2.22 |
| `composer/composer` | Packagist | From 2.0.0 | 2.2.22 |
| `composer/composer` | Packagist | From 2.3.0 | 2.6.4 |
| `composer/composer` | Packagist | From 2.3.0 | 2.6.4 |
| `composer` | Bitnami | All versions | 1.10.27, 2.2.21, 2.6.4 |
| `php-composer2` | SUSE:Linux Enterprise Module for Web and Scripting 15 SP4 | All versions | 2.2.3-150400.3.6.1 |
| `php-composer2` | SUSE:Linux Enterprise Module for Web and Scripting 15 SP5 | All versions | 2.2.3-150400.3.6.1 |
| `php-composer2` | openSUSE:Leap 15.4 | All versions | 2.2.3-150400.3.6.1 |
| `php-composer2` | openSUSE:Leap 15.5 | All versions | 2.2.3-150400.3.6.1 |
| `php-composer2` | openSUSE:Tumbleweed | All versions | 2.6.4-1.1 |

Products: Debian Debian Linux, Fedoraproject Fedora, Getcomposer Composer.

## How do I fix CVE-2023-43655?

Upgrade composer/composer to a fixed version for your release line: 1.10.27, 2.2.22 or 2.6.4.

## Is CVE-2023-43655 being exploited?

There is no known exploitation of CVE-2023-43655 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-2023-43655 and fix it if it is affected.

What it is: CVE-2023-43655 is a medium-severity code injection vulnerability in Debian Debian Linux, published on 29 Sep 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-43655 in the wild and no public exploit code.

Affected packages and fixed versions:
- composer/composer (Packagist): affected all versions; fixed in 1.10.27
- composer/composer (Packagist): affected all versions; fixed in 1.10.27
- composer/composer (Packagist): affected from 2.0.0; fixed in 2.2.22
- composer/composer (Packagist): affected from 2.0.0; fixed in 2.2.22
- composer/composer (Packagist): affected from 2.3.0; fixed in 2.6.4
- composer/composer (Packagist): affected from 2.3.0; fixed in 2.6.4
- composer (Bitnami): affected all versions; fixed in 1.10.27, 2.2.21, 2.6.4

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-2023-43655/ (Markdown: https://insights.sbomify.com/CVE-2023-43655/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-43655
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-43655
- OSV: https://osv.dev/vulnerability/CVE-2023-43655

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-43655/
Summaries are generated and may contain mistakes; the official description above is the record.