Verity Ultraseek before 5.7 allows remote attackers to use the server as a proxy for web attacks and host scanning via a direct request to the highlight/index.html script.
https://exchange.xforce.ibmcloud.com/vulnerabilities/30311
http://www.zerodayinitiative.com/advisories/ZDI-06-042.html
http://www.ultraseek.com/support/docs/RELNOTES.txt
http://www.securityfocus.com/bid/21120
http://www.securityfocus.com/archive/1/451847/100/0/threaded