CVE-2021-3129: 
PHP vulnerability analysis and mitigation

CVE-2021-3129 affects Ignition before version 2.5.2, as used in Laravel and other products. The vulnerability allows unauthenticated remote attackers to execute arbitrary code due to insecure usage of filegetcontents() and fileputcontents() functions. This vulnerability is particularly exploitable on sites using debug mode with Laravel versions before 8.4.2 (NVD).

The vulnerability received a CVSS v3.1 base score of 9.8 (CRITICAL) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. The issue stems from unsafe handling of file operations in the MakeViewVariableOptionalSolution component, which could allow attackers to exploit stream wrappers and execute arbitrary code. The vulnerability was fixed by implementing proper path validation to disallow stream wrappers and ensuring files end with .blade.php extension (Github PR).

The vulnerability enables unauthenticated remote attackers to execute arbitrary code on affected systems. This could lead to complete system compromise, allowing attackers to gain unauthorized access, modify data, and potentially take full control of the affected server (NVD).

Organizations should upgrade Ignition to version 2.5.2 or later, and Laravel to version 8.4.2 or later. If immediate patching is not possible, it is recommended to disable debug mode in Laravel applications. CISA has mandated federal agencies to apply vendor mitigations or discontinue product use if mitigations are unavailable (NVD).