CVE-2009-2726 Information

Description

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.

Reference

http://downloads.digium.com/pub/security/AST-2009-005.html http://labs.mudynamics.com/advisories/MU-200908-01.txt http://secunia.com/advisories/36227 http://www.securityfocus.com/archive/1/505669/100/0/threaded http://www.securityfocus.com/bid/36015 http://www.securitytracker.com/id?1022705 http://www.vupen.com/english/advisories/2009/2229