CVE-2013-5480: The DNS-over-TCP implementation in Cisco IOS 12.2 and 15.0 through 15.3, when NAT is used, allows remote at...

Security readout for executives and security teams

CVE-2013-5480 is a Cisco IOS NAT-related denial-of-service issue. On affected IOS 12.2 and 15.0 through 15.3 devices using NAT, crafted IPv4 DNS-over-TCP traffic can force a device reload, creating an outage risk for routing or edge infrastructure. Exposure is most likely on Cisco IOS routers running 12.2 or 15.0 through 15.3 with NAT enabled and reachable DNS-over-TCP IPv4 traffic paths. Devices not using NAT or not running the affected IOS trains are not shown as affected by the supplied sources. Treat this as a high-priority infrastructure availability risk if affected Cisco IOS NAT devices remain in service. It can reload network equipment remotely, but the supplied evidence does not show active exploitation or confirmed exposure in any specific environment. Mitigation focus: Identify Cisco IOS devices running 12.2 or 15.0 through 15.3.; Check Cisco advisory cisco-sa-20130925-nat for fixed software and official workarounds.; Prioritize NAT-enabled edge or transit devices with DNS-over-TCP exposure..

Prepared

Jun 14, 2026, 15:32 UTC (UTC+00:00)

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