fwknop before 2.0.3 does not properly validate IP addresses, which allows remote authenticated users to cause a denial of service (server crash) via a long IP address.
www.cipherdyne.org/blog/2012/09/software-release-fwknop-2.0.3.html
www.cipherdyne.org/cgi-bin/gitweb.cgi?p=fwknop.git;a=commitdiff;h=263fa01f2af1d336961df320f1c7a9ea84ddac9a
www.cipherdyne.org/cgi-bin/gitweb.cgi?p=fwknop.git;a=commitdiff;h=f4c16bc47fc24a96b63105556b62d61c1ba7d799
www.openwall.com/lists/oss-security/2012/09/19/2
www.openwall.com/lists/oss-security/2012/09/20/2
www.openwall.com/lists/oss-security/2012/09/20/4
exchange.xforce.ibmcloud.com/vulnerabilities/79568