Critical FreePBX Vulnerabilities Allow Authentication Bypass and Remote Code Execution

FreePBX, the open-source IP PBX platform, has patched several critical vulnerabilities in its Endpoint Manager module that could allow attackers to bypass authentication and achieve remote code execution. Researchers from Horizon3.ai identified three high-severity flaws: CVE-2025-66039 (authentication bypass via forged Basic Auth headers when 'webserver' authorization is enabled), CVE-2025-61675 (multiple SQL injection vulnerabilities across several endpoints), and CVE-2025-61678 (arbitrary file upload enabling PHP webshell deployment). These vulnerabilities, when chained, allow unauthenticated attackers to gain full control over affected FreePBX instances, posing a significant risk to business communications infrastructure.

The authentication bypass is not present in the default configuration but becomes exploitable if certain advanced settings are enabled. Attackers can exploit these flaws to access protected endpoints, manipulate the underlying SQL database, and upload malicious files for command execution. The vulnerabilities were responsibly disclosed to FreePBX maintainers, and patches have been released. Organizations using FreePBX, especially those with non-default authentication settings, are urged to update immediately to mitigate the risk of compromise.