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.

Cisco IOS 12.1 through 12.4, when Cisco Unified Communications Manager Express (CME) or Cisco Unified Survivable Remote Site Telephony (SRST) is enabled, allows remote attackers to cause a denial of service (device reload) via a malformed Skinny Client Control Protocol (SCCP) message, aka Bug ID CSCsz48614, the "SCCP Packet Processing Denial of Service 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 12.1 through 12.4, when Cisco Unified Communications Manager Express (CME) or Cisco Unified Survivable Remote Site Telephony (SRST) is enabled, allows remote attackers to cause a denial of service (device reload) via a malformed Skinny Client Control Protocol (SCCP) message, aka Bug ID CSCsz49741, the "SCCP Request Handling Denial of Service Vulnerability."

Unspecified vulnerability in Cisco IOS 12.2XNA, 12.2XNB, 12.2XNC, 12.2XND, 12.4T, 12.4XZ, and 12.4YA, when Zone-Based Policy Firewall SIP Inspection is enabled, allows remote attackers to cause a denial of service (device reload) via a crafted SIP transit packet, aka Bug ID CSCsr18691.

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.

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 malformed packets, aka Bug ID CSCsx70889.

Unspecified vulnerability in Cisco IOS 12.2 and 12.4, when SSLVPN sessions, SSH sessions, or IKE encrypted nonces are enabled, allows remote attackers to cause a denial of service (device reload) via a crafted encrypted packet, aka Bug ID CSCsq24002.

Race condition in the Firewall Authentication Proxy feature in Cisco IOS 12.0 through 12.4 allows remote attackers to bypass authentication, or bypass the consent web page, via a crafted request, aka Bug ID CSCsy15227.