CVE-2000-0268: Cisco 3660 Router

Medium severity, CVSS 5.0. EPSS: 1.7% chance of exploitation in the next 30 days.

Cisco IOS 11.x and 12.x allows remote attackers to cause a denial of service by sending the ENVIRON option to the Telnet daemon before it is ready to accept it, which causes the system to reboot.

Affected products

• Cisco 3660 Router: any version
• Cisco 7100 Router: any version
• Cisco 7200 Router: any version
• Cisco 7500 Router: any version
• Cisco Accesspath: version ls-3 only; version ts-3 only; version vs-3 only
• Cisco AS5200: any version
• Cisco AS5300: any version
• Cisco AS5800: any version
• Cisco IOS: version 11.3aa only; version 12.0(2) only; version 12.0(2)xc only; version 12.0(2)xd only; version 12.0(2)xf only; version 12.0(2)xg only; …
• Cisco System Controller 3640: any version
• Cisco UBR7200: any version
• Cisco Voice Gateway AS5800: any version

Published 2000-04-20. Last modified 2026-06-16.