CVE-2011-3273: Cisco IOS

High severity, CVSS 7.8. EPSS: 1.8% chance of exploitation in the next 30 days.

Memory leak in Cisco IOS 15.0 through 15.1, when IPS or Zone-Based Firewall (aka ZBFW) is configured, allows remote attackers to cause a denial of service (memory consumption or device crash) via vectors that trigger many session creation flows, aka Bug ID CSCti79848.

Affected products

• Cisco IOS: version 15.0 only; version 15.0m only; version 15.0sg only; version 15.0xa only; version 15.0xo only; version 15.1 only; …

Published 2011-10-03. Last modified 2026-06-16.