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.
Multiple buffer overflows in the voicemail functionality in Asterisk 1.4.x before 1.4.13, when using IMAP storage, might allow (1) remote attackers to execute arbitrary code via a long combination of Content-type and Content-description headers, or (2) local users to execute arbitrary code via a long combination of astspooldir, voicemail context, and voicemail mailbox fields. NOTE: vector 2 requires write access to Asterisk configuration files.