Description
OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.7, a logic flaw in the OPNsense lockout_handler allows an unauthenticated attacker to continuously reset the authentication failure counter for their IP address. By interjecting a crafted username containing a success keyword ("Accepted" or "Successful login") between normal brute-force attempts, an attacker can prevent the failure counter from ever reaching the lockout threshold. This vulnerability is fixed in 26.1.7.
Problem types
CWE-307: Improper Restriction of Excessive Authentication Attempts
Product status
References
gist.github.com/sopex/b9786e72e2a5d9b1bbd81ed8477c351b
github.com/...e/core/security/advisories/GHSA-h3vx-4q27-rc42