CVE-2011-3273: Memory leak in Cisco IOS 15.0 through 15.1, when IPS or Zone-Based Firewall (aka ZBFW) is configured, allow...

Security readout for executives and security teams

This issue can make certain Cisco IOS routers or firewalls run out of memory and potentially crash. It only applies when Cisco IOS 15.0 through 15.1 is running with IPS or Zone-Based Firewall configured. The available source bundle does not provide CVSS, fixed releases, or confirmed exploitation evidence. Exposure is most likely on legacy Cisco IOS 15.0 or 15.1 devices with IPS or ZBFW enabled. Organizations without those features enabled, or without those IOS branches, are less likely exposed based on the provided description. Treat as a legacy network stability risk. Urgency depends on whether affected Cisco IOS devices still carry critical traffic with IPS or ZBFW enabled. Absence of KEV evidence lowers exploitation urgency, but device crashes can still create business outages. Mitigation focus: Identify Cisco IOS 15.0 and 15.1 devices in the environment.; Confirm whether IPS or Zone-Based Firewall is configured on those devices.; Review Cisco advisory guidance for affected releases and fixed software..

Prepared

Jun 27, 2026, 17:48 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.