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.

The SIP channel driver in Asterisk Open Source 1.4.x before 1.4.17, Business Edition before C.1.0-beta8, AsteriskNOW before beta7, Appliance Developer Kit before Asterisk 1.4 revision 95946, and Appliance s800i 1.0.x before 1.0.3.4 allows remote attackers to cause a denial of service (daemon crash) via a BYE message with an Also (Also transfer) header, which triggers a NULL pointer dereference.

The SIP channel driver (chan_sip) in Asterisk Open Source 1.4.x before 1.4.11, AsteriskNOW before beta7, Asterisk Appliance Developer Kit 0.x before 0.8.0, and s800i (Asterisk Appliance) 1.x before 1.0.3 allows remote attackers to cause a denial of service (memory exhaustion) via a SIP dialog that causes a large number of history entries to be created.

Asterisk Open Source 1.4.5 through 1.4.11, when configured to use an IMAP voicemail storage backend, allows remote attackers to cause a denial of service via an e-mail with an "invalid/corrupted" MIME body, which triggers a crash when the recipient listens to voicemail.

The Skinny channel driver (chan_skinny) in Asterisk before 1.2.22 and 1.4.x before 1.4.8, Business Edition before B.2.2.1, AsteriskNOW before beta7, Appliance Developer Kit before 0.5.0, and s800i before 1.0.2 allows remote attackers to cause a denial of service (crash) via a certain data length value in a crafted packet, which results in an "overly large memcpy."

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.

The ooh323 channel driver in Asterisk Addons 1.2.x before 1.2.9 and Asterisk-Addons 1.4.x before 1.4.7 creates a remotely accessible TCP port that is intended solely for localhost communication, and interprets some TCP application-data fields as addresses of memory to free, which allows remote attackers to cause a denial of service (daemon crash) via crafted TCP packets.

The IAX2 channel driver (chan_iax2) in Asterisk before 1.2.22 and 1.4.x before 1.4.8, Business Edition before B.2.2.1, AsteriskNOW before beta7, Appliance Developer Kit before 0.5.0, and s800i before 1.0.2 allows remote attackers to cause a denial of service (crash) via a crafted (1) LAGRQ or (2) LAGRP frame that contains information elements of IAX frames, which results in a NULL pointer dereference when Asterisk does not properly set an associated variable.

A memory exhaustion vulnerability exists in Asterisk Open Source 13.x before 13.15.1 and 14.x before 14.4.1 and Certified Asterisk 13.13 before 13.13-cert4, which can be triggered by sending specially crafted SCCP packets causing an infinite loop and leading to memory exhaustion (by message logging in that loop).