CVE-2006-0805: Francisco Burzi PHP-Nuke

High severity, CVSS 7.5. EPSS: 3% chance of exploitation in the next 30 days.

The CAPTCHA functionality in php-Nuke 6.0 through 7.9 uses fixed challenge/response pairs that only vary once per day based on the User Agent (HTTP_USER_AGENT), which allows remote attackers to bypass CAPTCHA controls by fixing the User Agent, performing a valid challenge/response, then replaying that pair in the random_num and gfx_check parameters.

Affected products

• Francisco Burzi PHP-Nuke: version 6.0 only; version 6.5 only; version 6.5_beta1 only; version 6.5_final only; version 6.5_rc1 only; version 6.5_rc2 only; …

Published 2006-02-21. Last modified 2026-06-16.