The SIP channel driver in Asterisk Open Source 1.8.x before 1.8.20.2, 10.x before 10.12.2, and 11.x before 11.2.2; Certified Asterisk 1.8.15 before 1.8.15-cert2; Asterisk Business Edition (BE) C.3.x before C.3.8.1; and Asterisk Digiumphones 10.x-digiumphones before 10.12.2-digiumphones exhibits different behavior for invalid INVITE, SUBSCRIBE, and REGISTER transactions depending on whether the user account exists, which allows remote attackers to enumerate account names by (1) reading HTTP status codes, (2) reading additional text in a 403 (aka Forbidden) response, or (3) observing whether certain retransmissions occur.

main/http.c in the HTTP server in Asterisk Open Source 1.8.x before 1.8.20.2, 10.x before 10.12.2, and 11.x before 11.2.2; Certified Asterisk 1.8.15 before 1.8.15-cert2; and Asterisk Digiumphones 10.x-digiumphones before 10.12.2-digiumphones does not properly restrict Content-Length values, which allows remote attackers to conduct stack-consumption attacks and cause a denial of service (daemon crash) via a crafted HTTP POST request. NOTE: this vulnerability exists because of an incorrect fix for CVE-2012-5976.

Incomplete blacklist vulnerability in main/manager.c in Asterisk Open Source 1.8.x before 1.8.15.1 and 10.x before 10.7.1, Certified Asterisk 1.8.11 before 1.8.11-cert6, Asterisk Digiumphones 10.x.x-digiumphones before 10.7.1-digiumphones, and Asterisk Business Edition C.3.x before C.3.7.6 allows remote authenticated users to execute arbitrary commands by leveraging originate privileges and providing an ExternalIVR value in an AMI Originate action.

chan_skinny.c in the Skinny (aka SCCP) channel driver in Certified Asterisk 1.8.11-cert before 1.8.11-cert2 and Asterisk Open Source 1.8.x before 1.8.12.1 and 10.x before 10.4.1 allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) by closing a connection in off-hook mode.

Heap-based buffer overflow in chan_skinny.c in the Skinny channel driver in Asterisk Open Source 1.6.2.x before 1.6.2.24, 1.8.x before 1.8.11.1, and 10.x before 10.3.1 allows remote authenticated users to cause a denial of service or possibly have unspecified other impact via a series of KEYPAD_BUTTON_MESSAGE events.

chan_sip.c in the SIP channel driver in Asterisk Open Source 1.8.x before 1.8.11.1 and 10.x before 10.3.1 and Asterisk Business Edition C.3.x before C.3.7.4, when the trustrpid option is enabled, allows remote authenticated users to cause a denial of service (daemon crash) by sending a SIP UPDATE message that triggers a connected-line update attempt without an associated channel.

main/manager.c in the Manager Interface in Asterisk Open Source 1.6.2.x before 1.6.2.24, 1.8.x before 1.8.11.1, and 10.x before 10.3.1 and Asterisk Business Edition C.3.x before C.3.7.4 does not properly enforce System class authorization requirements, which allows remote authenticated users to execute arbitrary commands via (1) the originate action in the MixMonitor application, (2) the SHELL and EVAL functions in the GetVar manager action, or (3) the SHELL and EVAL functions in the Status manager action.

chan_sip.c in Asterisk Open Source 1.8.x before 1.8.8.2 and 10.x before 10.0.1, when the res_srtp module is used and media support is improperly configured, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted SDP message with a crypto attribute and a (1) video or (2) text media type, as demonstrated by CSipSimple.

chan_sip.c in the SIP channel driver in Asterisk Open Source 1.8.x before 1.8.7.1 and 10.x before 10.0.0-rc1 does not properly initialize variables during request parsing, which allows remote authenticated users to cause a denial of service (daemon crash) via a malformed request.

Asterisk Open Source 1.6.0.x before 1.6.0.22, 1.6.1.x before 1.6.1.14, and 1.6.2.x before 1.6.2.2, and Business Edition C.3 before C.3.3.2, allows remote attackers to cause a denial of service (daemon crash) via an SIP T.38 negotiation with an SDP FaxMaxDatagram field that is (1) missing, (2) modified to contain a negative number, or (3) modified to contain a large number.