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.
bugs.digium.com/view.php?id=12607
downloads.digium.com/pub/security/AST-2008-008.html
secunia.com/advisories/30517
secunia.com/advisories/34982
security.gentoo.org/glsa/glsa-200905-01.xml
svn.digium.com/view/asterisk?view=rev&revision=120109
www.securityfocus.com/archive/1/493020/100/0/threaded
www.securitytracker.com/id?1020166
www.vupen.com/english/advisories/2008/1731
exchange.xforce.ibmcloud.com/vulnerabilities/42823
www.exploit-db.com/exploits/5749