Cisco IOS 12.2 through 12.4, when certain PMTUD, SNAT, or window-size configurations are used, allows remote attackers to cause a denial of service (infinite loop, and device reload or hang) via a TCP segment with crafted options, aka Bug ID CSCsz75186.

Unspecified vulnerability in the SIP implementation in Cisco IOS 12.3 and 12.4 allows remote attackers to execute arbitrary code via a malformed SIP message, aka Bug ID CSCsz89904, the "SIP Packet Parsing Arbitrary Code Execution Vulnerability."

Unspecified vulnerability in the SIP implementation in Cisco IOS 12.3 and 12.4 allows remote attackers to execute arbitrary code via a malformed SIP message, aka Bug ID CSCsz48680, the "SIP Message Processing Arbitrary Code Execution Vulnerability."

Unspecified vulnerability in Cisco IOS 12.0 through 12.4, IOS XE 2.1.x through 2.3.x before 2.3.2, and IOS XR 3.2.x through 3.4.3, when Multiprotocol Label Switching (MPLS) and Label Distribution Protocol (LDP) are enabled, allows remote attackers to cause a denial of service (device reload or process restart) via a crafted LDP packet, aka Bug IDs CSCsz45567 and CSCsj25893.

Cisco IOS 12.0 through 12.4, when IP-based tunnels and the Cisco Express Forwarding feature are enabled, allows remote attackers to cause a denial of service (device reload) via a malformed packet that is not properly handled during switching from one tunnel to a second tunnel, aka Bug IDs CSCsh97579 and CSCsq31776.

Unspecified vulnerability in Cisco IOS 12.2XNA, 12.2XNB, 12.2XNC, 12.2XND, 12.4MD, 12.4T, 12.4XZ, and 12.4YA allows remote attackers to cause a denial of service (device reload) via a crafted NTPv4 packet, aka Bug IDs CSCsu24505 and CSCsv75948.