OPAL versions 2.2.8 and below and Ekiga versions 2.0.9 and below suffer from a denial of service condition due to insufficiently validating the Content-Length field of a SIP request.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/60044/s21sec-037-en.txt
Source: https://packetstormsecurity.com/files/60044/s21sec-037-en.txt.html