Asterisk Open Source 1.8.x before 1.8.28.1, 11.x before 11.10.1, and 12.x before 12.3.1 and Certified Asterisk 1.8.15 before 1.8.15-cert6 and 11.6 before 11.6-cert3 allows remote attackers to cause a denial of service (connection consumption) via a large number of (1) inactive or (2) incomplete HTTP connections.

Asterisk Open Source 11.x before 11.10.1 and 12.x before 12.3.1 and Certified Asterisk 11.6 before 11.6-cert3 allows remote authenticated Manager users to execute arbitrary shell commands via a MixMonitor action.

The Publish/Subscribe Framework in the PJSIP channel driver in Asterisk Open Source 12.x before 12.3.1, when sub_min_expiry is set to zero, allows remote attackers to cause a denial of service (assertion failure and crash) via an unsubscribe request when not subscribed to the device.

Stack-based buffer overflow in the ast_uri_encode function in main/utils.c in Asterisk Open Source before 1.4.38.1, 1.4.39.1, 1.6.1.21, 1.6.2.15.1, 1.6.2.16.1, 1.8.1.2, 1.8.2.; and Business Edition before C.3.6.2; when running in pedantic mode allows remote authenticated users to execute arbitrary code via crafted caller ID data in vectors involving the (1) SIP channel driver, (2) URIENCODE dialplan function, or (3) AGI dialplan function.

The SIP channel driver in Asterisk Open Source 1.2.x before 1.2.34, 1.4.x before 1.4.26.1, 1.6.0.x before 1.6.0.12, and 1.6.1.x before 1.6.1.4; Asterisk Business Edition A.x.x, B.x.x before B.2.5.9, C.2.x before C.2.4.1, and C.3.x before C.3.1; and Asterisk Appliance s800i 1.2.x before 1.3.0.3 does not use a maximum width when invoking sscanf style functions, which allows remote attackers to cause a denial of service (stack memory consumption) via SIP packets containing large sequences of ASCII decimal characters, as demonstrated via vectors related to (1) the CSeq value in a SIP header, (2) large Content-Length value, and (3) SDP.