CVE-2004-0551

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2004-08-06 · updated 2026-06-16

Description

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, allows remote attackers to cause a denial of service (system crash and reload) by sending invalid packets instead of the final ACK portion of the three-way handshake to the (1) Telnet, (2) HTTP, or (3) SSH services, aka "TCP-ACK DoS attack."

Affected products

Cisco Catalyst 2901: all versions
Cisco Catalyst 2902: all versions
Cisco Catalyst 2926: all versions
Cisco Catalyst 2926F: all versions
Cisco Catalyst 2926Gl: all versions
Cisco Catalyst 2926Gs: all versions
Cisco Catalyst 2926T: all versions
Cisco Catalyst 2948: all versions
Cisco Catalyst 2948-Ge-Tx: all versions
Cisco Catalyst 2948G-L3: all versions
Cisco Catalyst 2980G: all versions
Cisco Catalyst 2980G-A: all versions
Cisco Catalyst 4000: all versions
Cisco Catalyst 4500: all versions
Cisco Catalyst 4503: all versions
Cisco Catalyst 4506: all versions
Cisco Catalyst 4507R: all versions
Cisco Catalyst 4510R: all versions
Cisco Catalyst 4912G: all versions
Cisco Catalyst 5000: all versions
Cisco Catalyst 6000 Ws-Svc-Nam-1: 2.2(1a), 3.1(1a)
Cisco Catalyst 6000 Ws-Svc-Nam-2: 2.2(1a), 3.1(1a)
Cisco Catalyst 6000 Ws-X6380-Nam: 2.1(2), 3.1(1a)
Cisco Catos: 2.1(1), 2.1(2), 2.1(3), 2.1(4), 2.1(5), 2.1(6) (+206)

References

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