CVE-2023-43655 : What You Need to Know

A remote code execution vulnerability via a web-accessible

composer.phar

has been identified in Composer, a popular dependency manager for PHP.

Understanding CVE-2023-43655

This vulnerability can be exploited when users publish a

composer.phar

file to a web server and have

register_argc_argv

enabled in PHP configuration. Attackers can execute remote code on the server, leading to severe consequences.

What is CVE-2023-43655?

Composer users are at risk of remote code execution if the

composer.phar

file is accessible on a web server with specific PHP settings.

The Impact of CVE-2023-43655

The vulnerability can result in unauthorized code execution, compromising system confidentiality, integrity, availability, and potentially leading to further exploitation of the server.

Technical Details of CVE-2023-43655

The vulnerability in Composer affects versions 2.6.4, 2.2.21, and 1.10.27, with patches available in subsequent versions. Users are urged to upgrade to secure their systems.

Vulnerability Description

Users running affected versions of Composer are advised to upgrade to versions 2.6.4, 2.2.22, or 1.10.27 to mitigate the remote code execution risk. Disabling

register_argc_argv

in PHP configuration can also prevent exploitation.

Affected Systems and Versions

Vendor: Composer
Product: Composer
Affected Versions:
2.6.4, 2.2.21, 1.10.27

= 2.0, < 2.2.22

< 1.10.27

Exploitation Mechanism

Attackers can exploit the vulnerability by executing arbitrary code through a web-accessible

composer.phar

file when specific PHP settings are enabled.

Mitigation and Prevention

To address CVE-2023-43655, users of Composer should take immediate upgrade steps and adopt long-term security measures.

Immediate Steps to Take

Upgrade to Composer versions 2.6.4, 2.2.22, or 1.10.27
Disable

register_argc_argv

in PHP configuration

Long-Term Security Practices

Regularly monitor Composer security advisories
Avoid publishing

composer.phar

files to web-accessible servers

Patching and Updates

Stay informed about security updates from Composer, apply patches promptly, and follow best practices to enhance system security.