The Asterisk Extension Language (AEL) in pbx/pbx_ael.c in Asterisk does not properly generate extensions, which allows remote attackers to execute arbitrary extensions and have an unknown impact by specifying an invalid extension in a certain form.

The channel driver in Asterisk before 1.2.17 and 1.4.x before 1.4.2 allows remote attackers to cause a denial of service (crash) via a SIP INVITE message with an SDP containing one valid and one invalid IP address.

Asterisk 1.4 before 1.4.1 and 1.2 before 1.2.16 allows remote attackers to cause a denial of service (crash) by sending a Session Initiation Protocol (SIP) packet without a URI and SIP-version header, which results in a NULL pointer dereference.

Unspecified vulnerability in the SIP channel driver (channels/chan_sip.c) in Asterisk 1.2.x before 1.2.13 and 1.4.x before 1.4.0-beta3 allows remote attackers to cause a denial of service (resource consumption) via unspecified vectors that result in the creation of "a real pvt structure" that uses more resources than necessary.

Integer overflow in the get_input function in the Skinny channel driver (chan_skinny.c) in Asterisk 1.0.x before 1.0.12 and 1.2.x before 1.2.13, as used by Cisco SCCP phones, allows remote attackers to execute arbitrary code via a certain dlen value that passes a signed integer comparison and leads to a heap-based buffer overflow.

Stack-based buffer overflow in channels/chan_mgcp.c in MGCP in Asterisk 1.0 through 1.2.10 allows remote attackers to execute arbitrary code via a crafted audit endpoint (AUEP) response.

Asterisk 1.2.10 supports the use of client-controlled variables to determine filenames in the Record function, which allows remote attackers to (1) execute code via format string specifiers or (2) overwrite files via directory traversals involving unspecified vectors, as demonstrated by the CALLERIDNAME variable.

Buffer overflow in the get_msg_text of chan_sip.c in the Session Initiation Protocol (SIP) protocol implementation for Asterisk releases before August 15, 2003, allows remote attackers to execute arbitrary code via certain (1) MESSAGE or (2) INFO requests.