'You've Got Cross-Site Scripting'

Full Disclosure, sla.ckers.org, and other hacker forums: These are not the places where you first want to learn about a cross-site scripting vulnerability on your Website. Nor do you want to find out the hard way -- when it's been exploited.

So XSSed.com, a site dedicated to archiving publicly disclosed XSS bugs, is now offering a free email alert service that notifies you as soon as an XSS vulnerability affecting your Website gets indexed to its archive. XSSed claims to have the industry's largest XSS archive, with over 17,000 disclosed vulnerabilities as of this posting.

The idea is to give Website owners a jump on fixing the bugs on their site with the early-warning alert system. "We all know that this kind of vulnerability can be fixed in a few minutes -- even Google usually fixes vulnerabilities on the same day that they are released, so we believe all the Webmasters can fix the vulnerabilities before they are exploited, thanks to this feature," says Dimitris Pagkalos, one of XSSed.com's site owners.

And this could be just the first phase of this alert system. "If we see that this is not enough, we will think about adding another window of time between the validation and the public index of each XSS vulnerability," he says. "That way, Webmasters would have access to the specific vulnerabilities in advance."

XSSed.com is frequented by Microsoft, Yahoo, PayPal, and CERTS from all over the globe, according to its founders. The site relies on submissions for its archive, and also includes XSS vulns from other IT security forums and sources.

"XSSed is not disclosing cross-site scripting issues affecting online properties. It is just indexing XSS vulnerabilities that are already public," Pagkalos says. "Unlike Full Disclosure and sla.ckers.org, here at XSSed we mirror all valid submitted XSS issues, which are then also indexed in search engines in order to quickly reach the attention of their owner."

Pagkalos notes that although XSSed.com is the central archive for XSS bugs, there are still millions of other XSS bugs out there. Pagkalos and his colleague Kevin Fernandez also categorize XSS vulnerabilities by flagging high-profile sites like government, military, or high-page rank ones, for instance.

XSSed also includes related vulnerabilities on its site that affect clients, such as HTTP response-splitting, open redirects, and other phishing-type issues.

Security experts say XSSed's new service could help researchers as well as Website owners. "If the early-warning alert catches on, this could be a great medium for allowing people newer in the security field to test the waters while at the same time [offer] a safer way for the security testers to commit full disclosure if the site owner opts-in to the alerts," says sla.ckers.org member and researcher Rodney "Kyran" Gladue.

Still, there's always the risk of a hacker taking advantage of the system. "There needs to be a way to verify ownership of a Website in the early-alert system," Gladue says. "Otherwise, attackers could subscribe to the service under popular Websites and wait for a nice vulnerability to arise, posted by someone else."

Have a comment on this story? Please click "Discuss" below. If you'd like to contact Dark Reading's editors directly, send us a message.