The TCL shell in Cisco IOS 12.2(14)S before 12.2(14)S16, 12.2(18)S before 12.2(18)S11, and certain other releases before 25 January 2006 does not perform Authentication, Authorization, and Accounting (AAA) command authorization checks, which may allow local users to execute IOS EXEC commands that were prohibited via the AAA configuration, aka Bug ID CSCeh73049.

Cross-site scripting (XSS) vulnerability in Cisco IOS Web Server for IOS 12.0(2a) allows remote attackers to inject arbitrary web script or HTML by (1) packets containing HTML that an administrator views via an HTTP interface to the contents of memory buffers, as demonstrated by the URI /level/15/exec/-/buffers/assigned/dump; or (2) sending the router Cisco Discovery Protocol (CDP) packets with HTML payload that an administrator views via the CDP status pages. NOTE: these vectors were originally reported as being associated with the dump and packet options in /level/15/exec/-/show/buffers.

Cisco IOS 12.0 to 12.4 might allow remote attackers to execute arbitrary code via a heap-based buffer overflow in system timers. NOTE: this issue does not correspond to a specific vulnerability, rather a general weakness that only increases the feasibility of exploitation of any vulnerabilities that might exist. Such design-level weaknesses normally are not included in CVE, so perhaps this issue should be REJECTed.

Cisco IOS 12.0 through 12.4 and IOS XR before 3.2, with IPv6 enabled, allows remote attackers on a local network segment to cause a denial of service (device reload) and possibly execute arbitrary code via a crafted IPv6 packet.

Cisco IOS 12.2T through 12.4 allows remote attackers to bypass Authentication, Authorization, and Accounting (AAA) RADIUS authentication, if the fallback method is set to none, via a long username.

Cisco IOS 12.0S through 12.3YH allows remote attackers to cause a denial of service (device restart) via a crafted IPv6 packet.

Cisco IOS 12.0 through 12.3YL, with BGP enabled and running the bgp log-neighbor-changes command, allows remote attackers to cause a denial of service (device reload) via a malformed BGP packet.

Secure Shell (SSH) 2 in Cisco IOS 12.0 through 12.3 allows remote attackers to cause a denial of service (device reload) (1) via a username that contains a domain name when using a TACACS+ server to authenticate, (2) when a new SSH session is in the login phase and a currently logged in user issues a send command, or (3) when IOS is logging messages and an SSH session is terminated while the server is sending data.

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.

Cisco IOS 11.x and 12.0 through 12.2 allows remote attackers to cause a denial of service (traffic block) by sending a particular sequence of IPv4 packets to an interface on the device, causing the input queue on that interface to be marked as full.

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.