CVE-2013-5546: The TCP reassembly feature in Cisco IOS XE 3.7 before 3.7.3S and 3.8 before 3.8.1S on 1000 ASR devices allo...

Security readout for executives and security teams

This flaw can let a remote attacker crash and reload affected Cisco ASR 1000 routers by sending large TCP packets that hit NAT or ALG processing. The business risk is network interruption, not disclosed data theft. Urgency depends on whether affected IOS XE versions are still running on production routing paths. Exposure is limited to Cisco ASR 1000 devices running the named vulnerable IOS XE trains, especially where NAT or ALG traffic reaches TCP reassembly. The bundle does not identify other Cisco platforms or later release trains as affected. Prioritize remediation where affected ASR 1000 routers support internet edge, customer connectivity, or critical NAT services. A successful attack could create an outage, but the available sources do not show confirmed real-world exploitation. Mitigation focus: Inventory Cisco ASR 1000 routers and their IOS XE versions.; Upgrade IOS XE 3.7 systems to 3.7.3S or later.; Upgrade IOS XE 3.8 systems to 3.8.1S or later..

Prepared

Jun 14, 2026, 15:13 UTC (UTC+00:00)

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