José Miguel Esparza discovered that insufficient input validation is performed on SIP protocol header field 'Content-Length' by opal library used by ekiga. This flaw can be used to write '\0' byte to attacker-controlled address and crash ekiga. Ekiga 2.0.10 using opal library 2.2.10 was released to address this issue.

Ekiga 2.0.10 release notes: http://mail.gnome.org/archives/ekiga-list/2007-September/msg00103.html

CVS commit pointed out by upstream: http://openh323.cvs.sourceforge.net/openh323/opal/src/sip/sippdu.cxx?r1=2.83.2.19&r2=2.83.2.20&pathrev=Phobos (some of the previous commits may be required to get complete checks / fix)