FastCGI Vulnerability Enables Arbitrary Code Execution in Embedded Systems

EXECUTIVE SUMMARY:

A vulnerability CVE-2025-23016 has been identified in the FastCGI library, which is used to bridge web servers like Nginx or Apache with third-party web applications. The flaw, stemming from improper handling of parameter lengths, can lead to an exploitable heap overflow, particularly affecting low-power embedded systems. The vulnerability is in the ReadParams() function, where an integer overflow occurs on 32-bit systems due to incorrect memory allocation, resulting in a heap overflow when large data is copied into an undersized buffer. Exploiting this flaw could allow an attacker to corrupt memory structures and execute arbitrary code on affected devices. This vulnerability is especially concerning in embedded systems, which often lack modern exploit mitigations. It ensures that proper memory handling and bounds checking are implemented in applications can help reduce the risk of exploitation. This flaw may also allow attackers to gain unauthorized access to sensitive data or disrupt device functionality. The CVSS score for this vulnerability is 9.4.