The FWDOWNL firmware-download implementation in Asterisk Open Source 1.0.x, 1.2.x before 1.2.30, and 1.4.x before 1.4.21.2; Business Edition A.x.x, B.x.x before B.2.5.4, and C.x.x before C.1.10.3; AsteriskNOW; Appliance Developer Kit 0.x.x; and s800i 1.0.x before 1.2.0.1 allows remote attackers to cause a denial of service (traffic amplification) via an IAX2 FWDOWNL request.

The IAX2 protocol implementation in Asterisk Open Source 1.0.x, 1.2.x before 1.2.30, and 1.4.x before 1.4.21.2; Business Edition A.x.x, B.x.x before B.2.5.4, and C.x.x before C.1.10.3; AsteriskNOW; Appliance Developer Kit 0.x.x; and s800i 1.0.x before 1.2.0.1 allows remote attackers to cause a denial of service (call-number exhaustion and CPU consumption) by quickly sending a large number of IAX2 (IAX) POKE requests.

Asterisk Open Source 1.0.x and 1.2.x before 1.2.29 and Business Edition A.x.x and B.x.x before B.2.5.3, when pedantic parsing (aka pedanticsipchecking) is enabled, allows remote attackers to cause a denial of service (daemon crash) via a SIP INVITE message that lacks a From header, related to invocations of the ast_uri_decode function, and improper handling of (1) an empty const string and (2) a NULL pointer.

The IAX2 channel driver (chan_iax2) in Asterisk 1.2 before revision 72630 and 1.4 before revision 65679, when configured to allow unauthenticated calls, sends "early audio" to an unverified source IP address of a NEW message, which allows remote attackers to cause a denial of service (traffic amplification) via a spoofed NEW message.

The IAX2 channel driver (chan_iax2) in Asterisk Open Source 1.0.x, 1.2.x before 1.2.28, and 1.4.x before 1.4.19.1; Business Edition A.x.x, B.x.x before B.2.5.2, and C.x.x before C.1.8.1; AsteriskNOW before 1.0.3; Appliance Developer Kit 0.x.x; and s800i before 1.1.0.3, when configured to allow unauthenticated calls, does not verify that an ACK response contains a call number matching the server's reply to a NEW message, which allows remote attackers to cause a denial of service (traffic amplification) via a spoofed ACK response that does not complete a 3-way handshake. NOTE: this issue exists because of an incomplete fix for CVE-2008-1923.

Unspecified vulnerability in Asterisk Open Source 1.2.x before 1.2.27, 1.4.x before 1.4.18.1 and 1.4.19-rc3; Business Edition A.x.x, B.x.x before B.2.5.1, and C.x.x before C.1.6.2; AsteriskNOW 1.0.x before 1.0.2; Appliance Developer Kit before 1.4 revision 109393; and s800i 1.0.x before 1.1.0.2; allows remote attackers to access the SIP channel driver via a crafted From header.

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.

Integer signedness error in format_jpeg.c in Asterisk 1.2.6 and earlier allows remote attackers to execute arbitrary code via a length value that passes a length check as a negative number, but triggers a buffer overflow when it is used as an unsigned length.

Directory traversal vulnerability in vmail.cgi in Asterisk 1.0.9 through 1.2.0-beta1 allows remote attackers to access WAV files via a .. (dot dot) in the folder parameter.