CVE-2004-1464: Cisco IOS Denial-of-Service Vulnerability

Medium severity, CVSS 5.9. Actively exploited: in CISA KEV since 2023-05-19. EPSS: 4.8% chance of exploitation in the next 30 days.

Cisco IOS 12.2(15) and earlier allows remote attackers to cause a denial of service (refused VTY (virtual terminal) connections), via a crafted TCP connection to the Telnet or reverse Telnet port.

Affected products

• Cisco IOS: up to and including 12.2\(15\)zj3

Published 2004-12-31. Last modified 2026-06-16.