CVE-2006-4430: Cisco Network Admission Control

Medium severity, CVSS 5.0. EPSS: 2% chance of exploitation in the next 30 days.

The Cisco Network Admission Control (NAC) 3.6.4.1 and earlier allows remote attackers to prevent installation of the Cisco Clean Access (CCA) Agent and bypass local and remote protection mechanisms by modifying (1) the HTTP User-Agent header or (2) the behavior of the TCP/IP stack. NOTE: the vendor has disputed the severity of this issue, stating that users cannot bypass authentication mechanisms.

Affected products

• Cisco Network Admission Control: up to and including 3.6.4.1
• Cisco Network Admission Control Manager And Server System Software: version 3.3 only; version 3.3.1 only; version 3.3.2 only; version 3.3.3 only; version 3.3.4 only; version 3.3.5 only; …

Published 2006-08-29. Last modified 2026-06-16.