Cisco : Security Vulnerabilities, CVEs, Published In 2000 (Denial of service) CVSS score >= 3

Buffer overflow in CiscoSecure ACS Server 2.4(2) and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary commands via a large TACACS+ packet.

Buffer overflow in CSAdmin module in CiscoSecure ACS Server 2.4(2) and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary commands via a large packet.

The HTTP server in Cisco IOS 12.0 through 12.1 allows local users to cause a denial of service (crash and reload) via a URL containing a "?/" string.

Buffer overflow in Cisco TACACS+ tac_plus server allows remote attackers to cause a denial of service via a malformed packet with a long length field.

The IOS HTTP service in Cisco routers and switches running IOS 11.1 through 12.1 allows remote attackers to cause a denial of service by requesting a URL that contains a %% string.

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.