CVE-2013-5509: Cisco Adaptive Security Appliance Software

High severity, CVSS 10.0. EPSS: 2.3% chance of exploitation in the next 30 days.

The SSL implementation in Cisco Adaptive Security Appliance (ASA) Software 9.0 before 9.0(2.6) and 9.1 before 9.1(2) allows remote attackers to bypass authentication, and obtain VPN access or administrative access, via a crafted X.509 client certificate, aka Bug ID CSCuf52468.

Affected products

• Cisco Adaptive Security Appliance Software: version 9.0 only; version 9.1 only

Published 2013-10-13. Last modified 2026-06-16.