The provider-edge MPLS NAT implementation in Cisco IOS 12.1 through 12.4 and 15.0 through 15.1, and IOS XE 3.1.xSG, allows remote attackers to cause a denial of service (device reload) via a malformed SIP packet to UDP port 5060, aka Bug ID CSCti98219.

The NAT implementation in Cisco IOS 12.1 through 12.4 and 15.0 through 15.1, and IOS XE 3.1.xSG, allows remote attackers to cause a denial of service (device reload or hang) via malformed NetMeeting Directory (aka Internet Locator Service or ILS) LDAP traffic, aka Bug ID CSCtd10712.

STCAPP (aka the SCCP telephony control application) on Cisco IOS before 15.0(1)XA1 does not properly handle multiple calls to a shared line, which allows remote attackers to cause a denial of service (port hang) by simultaneously ending two calls that were controlled by CallManager Express (CME), aka Bug ID CSCtd42552.

CallManager Express (CME) on Cisco IOS before 15.0(1)XA1 does not properly handle SIP TRUNK traffic that contains rate bursts and a "peculiar" request size, which allows remote attackers to cause a denial of service (memory consumption) by sending this traffic over a long duration, aka Bug ID CSCtb47950.

Cisco IOS before 15.0(1)XA1 does not clear the public key cache upon a change to a certificate map, which allows remote authenticated users to bypass a certificate ban by connecting with a banned certificate that had previously been valid, aka Bug ID CSCta79031.

Cisco IOS before 15.0(1)XA1, when certain TFTP debugging is enabled, allows remote attackers to cause a denial of service (device crash) via a TFTP copy over IPv6, aka Bug ID CSCtb28877.

Memory leak in Cisco IOS before 15.0(1)XA5 might allow remote attackers to cause a denial of service (memory consumption) by sending a crafted SIP REGISTER message over UDP, aka Bug ID CSCtg41733.

CallManager Express (CME) on Cisco IOS before 15.0(1)XA allows remote authenticated users to cause a denial of service (device crash) by using an extension mobility (EM) phone to interact with the menu for SNR number changes, aka Bug ID CSCta63555.

Memory leak in the gk_circuit_info_do_in_acf function in the H.323 implementation in Cisco IOS before 15.0(1)XA allows remote attackers to cause a denial of service (memory consumption) via a large number of calls over a long duration, as demonstrated by InterZone Clear Token (IZCT) test traffic, aka Bug ID CSCsz72535.

Cisco IOS before 15.0(1)XA does not properly handle IRC traffic during a specific time period after an initial reload, which allows remote attackers to cause a denial of service (device reload) via an attempted connection to a certain IRC server, related to a "corrupted magic value," aka Bug ID CSCso05336.

The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS before 15.0(1)XA5 allows remote attackers to cause a denial of service (CPU consumption and device hang) by sending many Router Advertisement (RA) messages with different source addresses, as demonstrated by the flood_router6 program in the thc-ipv6 package, aka Bug ID CSCti33534.

Cisco IOS 12.2 through 12.4 and 15.0 through 15.1, Cisco IOS XE 2.5.x and 2.6.x before 2.6.1, and Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 4.x, 5.x before 5.1(3g), 6.x before 6.1(4), and 7.x before 7.1(2) allow remote attackers to cause a denial of service (device reload or voice-services outage) via a malformed SIP INVITE message that triggers an improper call to the sipSafeStrlen function, aka Bug IDs CSCsz40392 and CSCsz43987.