The Linksys SPA941 VoIP Phone allows remote attackers to cause a denial of service (device reboot) via a 0377 (0xff) character in the From header, and possibly certain other locations, in a SIP INVITE request.
https://www.exploit-db.com/exploits/3792
https://www.exploit-db.com/exploits/3791
https://exchange.xforce.ibmcloud.com/vulnerabilities/33856
http://www.vupen.com/english/advisories/2007/1532
http://www.securitytracker.com/id?1017957
http://secunia.com/advisories/25031
http://lists.grok.org.uk/pipermail/full-disclosure/2007-April/053959.html