Gnuboard5 - Redirect Creation (CVE-2024-37656)

CVE-2024-37656 is an open redirect vulnerability in gnuboard5 version 5.5.16, where insufficient URL parameter verification in bbs/logout.php allows remote attackers to redirect users to malicious sites. This flaw can be exploited to steal sensitive information through phishing attacks or social engineering.

CrowdSec has been tracking this vulnerability and its exploits since 26th of November 2025.

Data from the CrowdSec community indicates that exploitation of CVE-2024-37656 is highly selective and intelligence-driven. Threat actors use advanced reconnaissance and carefully choose their targets, often as part of sophisticated campaigns or advanced persistent threat operations. Additionally, according to week-over-week analysis by CrowdSec, exploitation of CVE-2024-37656 is surging. Attack volumes are spiking well above historical norms, indicating widespread and escalating interest from threat actors. CVE-2024-37656 is currently experiencing high visibility and active exploitation across the internet.

Attackers exploit this vulnerability by sending requests to /bbs/logout.php or /gnuboard5/bbs/logout.php with a crafted url parameter, causing users to be redirected to attacker-controlled domains.