Security researchers have uncovered a major RCE threat affecting over 600 Laravel applications, triggered by leaked APP_KEYs found on public GitHub repositories.
Laravel’s APP_KEY, typically stored in .env files, is critical for encryption, authentication token generation, and data signing. When exposed, it can allow attackers to craft malicious payloads that trigger remote code execution via Laravel’s decrypt() function.
Technical Details:
- Leak Source: Public GitHub repos containing .env files with valid APP_KEY and APP_URL pairs
- Vulnerability Chain: Leaked key → Laravel decrypt() → PHP object deserialization → RCE
- Known CVEs:
- CVE-2018-15133 (original vector)
- CVE-2024-55556 (impacting newer Laravel versions using SESSION_DRIVER=cookie)
- Exploitation in the Wild: Used by the AndroxGh0st malware to scan for vulnerable Laravel servers
Why It Matters for Enterprises:
There is a direct RCE risk if your Laravel application has leaked APP_KEYs or uses insecure cookie-based session storage.
What makes this especially dangerous is that .env file leaks rarely stop at a single key. These files often contain cloud credentials, database passwords, and API tokens, multiplying the potential damage.
Even after a secret is scrubbed from a repository, it may still be cached, cloned, or indexed by third-party tools, meaning the threat persists unless the key is properly rotated and the environment is redeployed.
Recommendations:
- Scan for exposed secrets: Check public repos, build artifacts, and containers for .env files and keys.
- Rotate exposed APP_KEYs immediately, invalidate old sessions, and redeploy all affected systems.
- Avoid SESSION_DRIVER=cookie where possible to reduce deserialization attack surfaces.
- Implement continuous secret scanning in your CI/CD pipeline using tools like GitGuardian or open-source alternatives.
- Adopt secure-by-design patterns for handling secrets. Avoid storing sensitive config directly in code or containers.
OP Innovate Insight:
This attack vector reinforces a common theme: leaked credentials and insecure deserialization remain top entry points for threat actors. Through our WASP platform, we help clients detect configuration weaknesses and ensure that exposed secrets don’t become footholds for full-blown compromise.
Need help assessing the risk across your Laravel or PHP-based applications?
Reach out to our team at OP Innovate for a secure code review or targeted application penetration test.
Stay informed. Stay secure.
OP Innovate Research Team
