Remote Code Execution in Laravel via Concurrency::run Forgery

Executive Summary

Laravel's Concurrency::run process driver has a flaw where it can misinterpret forged internal result messages in child process output as legitimate framework output. This requires an attacker to craft specific malicious input that includes a complete JSON document followed by gzip magic bytes at the start of the child's standard output. If an application routes untrusted input into task output and uses Concurrency::run, this could lead to remote code execution.

Useful 0 Not Useful 0

Detection Guidance

Detection requires checking Laravel application versions and reviewing custom code that uses Concurrency::run with untrusted input. Verify if your Laravel version is below 12.71.0 or 13.40.0. Inspect application routes and tasks for improper handling of task output.

Useful 0 Not Useful 0

Impact Analysis

If your Laravel application uses Concurrency::run and routes untrusted input into task output, an attacker could exploit this to execute arbitrary code remotely. This could allow unauthorized access to your system, data theft, or further compromise of your application or infrastructure.

Useful 0 Not Useful 0

Mitigation Strategies

Upgrade Laravel to version 12.71.0 or 13.40.0 or later immediately. Review and modify any custom code that routes untrusted input into task output to prevent task output manipulation. Ensure no routes invoke Concurrency::run with attacker-controlled data.

Useful 0 Not Useful 0