Cisco IOS 12.4 and earlier, when using the crypto packages and SSL support is enabled, allows remote attackers to cause a denial of service via a malformed (1) ClientHello, (2) ChangeCipherSpec, or (3) Finished message during an SSL session.

Cisco IOS 9.x, 10.x, 11.x, and 12.x and IOS XR 2.0.x, 3.0.x, and 3.2.x allows remote attackers to cause a denial of service or execute arbitrary code via a crafted IP option in the IP header in a (1) ICMP, (2) PIMv2, (3) PGM, or (4) URD packet.

Memory leak in the TCP listener in Cisco IOS 9.x, 10.x, 11.x, and 12.x allows remote attackers to cause a denial of service by sending crafted TCP traffic to an IPv4 address on the IOS device.

Cisco IOS allows remote attackers to cause a denial of service (crash) via a crafted IPv6 Type 0 Routing header.

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.

Unspecified vulnerability in Stack Group Bidding Protocol (SGBP) support in Cisco IOS 12.0 through 12.4 running on various Cisco products, when SGBP is enabled, allows remote attackers on the local network to cause a denial of service (device hang and network traffic loss) via a crafted UDP packet to port 9900.