CVE-2011-0945: Memory leak in the Data-link switching (aka DLSw) feature in Cisco IOS 12.1 through 12.4 and 15.0 through 1...

Security readout for executives and security teams

This issue can let a remote attacker exhaust memory on affected Cisco IOS or IOS XE devices using DLSw over FST, potentially causing a router to reload or hang. The business impact is network outage, not data theft. Exposure depends on whether the vulnerable DLSw-over-FST feature is enabled and reachable. Most exposure is in legacy Cisco routing environments using DLSw over Fast Sequence Transport. Organizations without DLSw-over-FST usage are less likely to be affected. The source bundle does not identify specific hardware models. Treat this as a high-priority legacy network availability risk if affected Cisco devices still run DLSw over FST. It is less urgent where that feature is absent, but inventory validation is important because outages can affect core connectivity. Mitigation focus: Review Cisco advisory for fixed software appropriate to each device train.; Upgrade IOS XE 3.1.xS to 3.1.3S or later where applicable.; Upgrade IOS XE 3.2.xS to 3.2.1S or later where applicable..

Prepared

Jun 27, 2026, 18:09 UTC (UTC+00:00)

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