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) 6.x before 6.1(5)SU1, 7.x before 7.1(5), and 8.0 before 8.0(2) allow remote attackers to cause a denial of service (device reload or voice-services outage) via crafted SIP registration traffic over UDP, aka Bug IDs CSCtf72678 and CSCtf14987.

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) 6.x before 6.1(5), 7.0 before 7.0(2a)su3, 7.1su before 7.1(3b)su2, 7.1 before 7.1(5), and 8.0 before 8.0(1) allow remote attackers to cause a denial of service (device reload or voice-services outage) via a SIP REFER request with an invalid Refer-To header, aka Bug IDs CSCta20040 and CSCta31358.

The CTI Manager service in Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 4.x before 4.3(2)sr1a, 6.x before 6.1(3), 7.0x before 7.0(2), 7.1x before 7.1(2), and 8.x before 8.0(1) allows remote attackers to cause a denial of service (service failure) via a malformed message, aka Bug ID CSCsu31800.

Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 6.x before 6.1(5), 7.x before 7.1(3a)su1, and 8.x before 8.0(1) allows remote attackers to cause a denial of service (process failure) via a malformed SCCP (1) RegAvailableLines or (2) FwdStatReq message with an invalid Line number, aka Bug ID CSCtc47823.

Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 6.x before 6.1(5), 7.x before 7.1(3b)SU2, and 8.x before 8.0(1) allows remote attackers to cause a denial of service (process failure) via a malformed SIP REG message, related to an overflow of the Telephone-URL field, aka Bug ID CSCtc62362.

Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 4.x before 4.3(2)SR2, 6.x before 6.1(5), 7.x before 7.1(3a)su1, and 8.x before 8.0(1) allows remote attackers to cause a denial of service (process failure) via a malformed SCCP StationCapabilitiesRes message with an invalid MaxCap field, aka Bug ID CSCtc38985.

Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 5.x before 5.1(3g), 6.x before 6.1(4), 7.0.x before 7.0(2a)su1, and 7.1.x before 7.1(2) allows remote attackers to cause a denial of service (service restart) via malformed SIP messages, aka Bug ID CSCsz95423.

The IP Phone Personal Address Book (PAB) Synchronizer feature in Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 4.1, 4.2 before 4.2(3)SR4b, 4.3 before 4.3(2)SR1b, 5.x before 5.1(3e), 6.x before 6.1(3), and 7.0 before 7.0(2) sends privileged directory-service account credentials to the client in cleartext, which allows remote attackers to modify the CUCM configuration and perform other privileged actions by intercepting these credentials, and then using them in requests unrelated to the intended synchronization task, as demonstrated by (1) DC Directory account credentials in CUCM 4.x and (2) TabSyncSysUser account credentials in CUCM 5.x through 7.x.

The Certificate Authority Proxy Function (CAPF) service in Cisco Unified Communications Manager 5.x before 5.1(3e) and 6.x before 6.1(3) allows remote attackers to cause a denial of service (voice service outage) by sending malformed input over a TCP session in which the "client terminates prematurely."

The Certificate Authority Proxy Function (CAPF) service in Cisco Unified Communications Manager (CUCM) 4.1 before 4.1(3)SR7, 4.2 before 4.2(3)SR4, and 4.3 before 4.3(2) allows remote attackers to cause a denial of service (service crash) via malformed network traffic, aka Bug ID CSCsk46770.