Craft CMS Remote Code Execution (RCE) Vulnerability Security Advisory (CVE-2023-41892)

1. Apply Official Security Patch

The recommended mitigation is to upgrade Craft CMS to version 4.4.15 or later.

If you are using Composer, run the following command to update your installation:

# Update Craft CMS via Composer
composer update craftcms/cms

2. Temporary Mitigations (If patching is delayed)

If immediate patching is not feasible, implement the following temporary workarounds:

• Web Application Firewall (WAF) Rules:
• Deploy WAF rules to detect and block suspicious payloads containing object injection patterns (e.g., targeting guzzle or deserialization vectors).
• Harden PHP Configuration:
• Disable dangerous PHP functions in your php.ini configuration:

    disable_functions = exec,passthru,shell_exec,system,proc_open,popen,curl_exec,curl_multi_exec,parse_ini_file,show_source

• Network Access Control:
• Restrict access to the admin panel (/admin) and critical endpoints to trusted IP addresses only.

This vulnerability (CVE-2023-41892) is a critical Remote Code Execution (RCE) flaw in Craft CMS. The root cause lies in Code Injection (CWE-94) due to insufficient input validation and sanitization.

An unauthenticated attacker can exploit this vulnerability by sending malicious payloads via HTTP requests to specific endpoints. The attack vector leverages PHP's garbage collection mechanics or file upload handling to inject and execute arbitrary PHP code in the context of the web server.

Due to its low attack complexity and lack of authentication requirements, this vulnerability is highly susceptible to automated exploitation. A successful exploit allows attackers to execute system commands, potentially leading to database theft, backdoor installation, and lateral movement within the network.