CVE-2015-0645: The Layer 4 Redirect (L4R) feature in Cisco IOS XE 2.x and 3.x before 3.10.4S, 3.11 before 3.11.3S, 3.12 be...

Security readout for executives and security teams

CVE-2015-0645 is a Cisco IOS XE availability flaw. If a vulnerable router uses Layer 4 Redirect, malformed IPv4 or IPv6 traffic can make the device reload, disrupting network connectivity. The source bundle does not show active exploitation or a CVSS score. Exposure is most likely in environments running affected Cisco IOS XE 2.x or 3.x releases with Layer 4 Redirect enabled, including platforms covered by the referenced Cisco IOS XE advisory. Systems on fixed trains or without L4R exposure are less likely affected. Treat this as a high-priority network availability risk where affected IOS XE routers support critical traffic. There is no evidence in the bundle of active exploitation, but a router reload can create material business disruption. Mitigation focus: Check Cisco advisory guidance for the fixed IOS XE release for each affected train.; Prioritize upgrades for internet-facing or critical routing devices using L4R.; Review whether Layer 4 Redirect is enabled and required on affected devices..

Prepared

Jun 13, 2026, 22:56 UTC (UTC+00:00)

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