code-projects Plugin 4.1.2cu.5137 Buffer Overflow Vulnerability

A critical buffer overflow vulnerability, identified as CVE-2026-7503, has been discovered in code-projects Plugin version 4.1.2cu.5137. The vulnerability resides within the setWiFiMultipleConfig function in the /lib/cste_modules/wireless.so library, which is part of the /cgi-bin/cstecgi.cgi executable. Successful exploitation is achieved through manipulation of the wepkey2 argument, allowing for remote code execution. The vulnerability is considered highly critical due to the availability of a public exploit, increasing the likelihood of widespread exploitation and potential compromise of affected systems. This poses a significant threat to devices utilizing the vulnerable plugin version.

Attack Chain

1. Attacker identifies a system running code-projects Plugin 4.1.2cu.5137.
2. The attacker crafts a malicious HTTP request targeting the /cgi-bin/cstecgi.cgi endpoint.
3. The request includes a specially crafted payload for the wepkey2 argument within the setWiFiMultipleConfig function.
4. The vulnerable function setWiFiMultipleConfig processes the malicious input without proper bounds checking.
5. The oversized wepkey2 argument overflows the buffer, overwriting adjacent memory regions.
6. The attacker injects malicious code into the memory space via the buffer overflow.
7. The injected code executes, granting the attacker control over the affected system.

Impact

Successful exploitation of CVE-2026-7503 can lead to complete system compromise, allowing attackers to execute arbitrary code, steal sensitive information, or cause denial-of-service conditions. Due to the ready availability of an exploit, any system running the vulnerable code-projects plugin version 4.1.2cu.5137 is at immediate risk. The lack of specific victim numbers or sector targeting information in the provided source does not diminish the critical nature of the vulnerability given the high CVSS score (8.8) and public exploit.

Recommendation

• Deploy the Sigma rule “Detect Code-Projects WiFi Configuration Buffer Overflow Attempt” to your SIEM to detect exploitation attempts targeting the vulnerable setWiFiMultipleConfig function and monitor web server logs (cs-uri-query).
• Apply input validation and sanitization to prevent buffer overflows. This issue occurs within the /lib/cste_modules/wireless.so library called by /cgi-bin/cstecgi.cgi.
• Monitor network traffic for suspicious requests targeting the /cgi-bin/cstecgi.cgi endpoint, as this is the entry point for exploiting CVE-2026-7503.