CVE-2005-2105: Cisco IOS 12.2T through 12.4 allows remote attackers to bypass Authentication, Authorization, and Accountin...

Security readout for executives and security teams

Some Cisco IOS routers could let a remote user bypass RADIUS-based login checks when AAA fallback is configured as none. The issue depends on both IOS version and configuration, but it affects network control-plane access, so exposed management paths deserve prompt review. Exposure is most likely on legacy Cisco IOS 12.2T through 12.4 devices using RADIUS AAA with fallback set to none, especially where management access is reachable from untrusted networks. Treat this as a priority legacy network-infrastructure review. Business urgency is highest where affected routers remain reachable for administration or protect critical network paths. Mitigation focus: Inventory Cisco IOS 12.2T through 12.4 devices using RADIUS AAA.; Review AAA method lists for fallback configured as none.; Check Cisco’s advisory for supported fixed releases and vendor remediation..

Prepared

Jun 29, 2026, 19:30 UTC (UTC+00:00)

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