CVE-2005-3774: Cisco Pix

Medium severity, CVSS 5.0. EPSS: 18.2% chance of exploitation in the next 30 days.

Cisco PIX 6.3 and 7.0 allows remote attackers to cause a denial of service (blocked new connections) via spoofed TCP packets that cause the PIX to create embryonic connections that that would not produce a valid connection with the end system, including (1) SYN packets with invalid checksums, which do not result in a RST; or, from an external interface, (2) one byte of "meaningless data," or (3) a TTL that is one less than needed to reach the internal destination.

Affected products

• Cisco Pix: version 6.3 only; version 7.0 only

Published 2005-11-23. Last modified 2026-06-16.