CVE-2004-0551: Cisco CatOS 5.x before 5.5(20) through 8.x before 8.2(2) and 8.3(2)GLX, as used in Catalyst switches, allow...

Security readout for executives and security teams

This flaw can let a remote attacker crash and reload older Cisco Catalyst switches running affected CatOS versions. The trigger involves malformed connection handling against Telnet, HTTP, or SSH management services. Business impact is network disruption, not data theft, but exposed core switching infrastructure can make outages significant. Exposure is most likely where legacy Catalyst switches still run affected CatOS and allow Telnet, HTTP, or SSH management access from untrusted or broad network segments. Modern environments are less likely affected unless old switching infrastructure remains in service. Treat as high priority if legacy Cisco Catalyst switches remain in production. The direct risk is outage from device crash and reload. Confirm inventory first; remediation urgency depends on whether affected management services are reachable beyond tightly controlled admin networks. Mitigation focus: Upgrade affected CatOS releases to Cisco fixed versions or later.; Prioritize switches supporting critical network segments or internet-adjacent management paths.; Check Cisco advisory for supported workarounds and platform-specific guidance..

Prepared

Jun 30, 2026, 05:41 UTC (UTC+00:00)

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