Adobe Fixes Flash Authoring XSS VulnerabilitiesAdobe Fixes Flash Authoring XSS Vulnerabilities

Adobe has released two security bulletins that address cross-site scripting (XSS) vulnerabilities arising from its media authoring and content serving software.

The security bulletins cover Adobe's Dreamweaver CS3, Dreamweaver 8, Contribute CS3, Contribute 4 and Connect Enterprise Server for Windows and Mac OS.

"Input validation errors have been identified in code generated by Dreamweaver and Contribute which could lead to potential cross-site scripting attacks," Adobe explains in one of its bulletins. "Only customers who have used the Insert Flash Video command in Dreamweaver or Contribute may be vulnerable."

Rich Cannings, a senior information security engineer at Google, described the risks in a public Google Docs file earlier in January, noting that many Web authoring tools insert vulnerable ActionScript code into Flash (.SWF) files. He said that Google hacking queries could reveal hundreds of thousands of vulnerable .SWF files and that "a considerable percentage of major Internet sites are affected."

These files could be used to facilitate cross-site scripting attacks. "If a Web application is vulnerable to XSS, and an attacker lures a user of the vulnerable Web application to click on a link, then the attacker gains complete control of the user's session in the Web application," Cannings explained in his post. "The attacker can use JavaScript to perform any action on behalf of the user (for example, perform a transaction on an online banking system) or change the way the Web site appears to the user (for example, perform a phishing attack)."

XSS vulnerabilities are not uncommon. The site XSSed.com maintains a list of reported XSS holes in Web sites. On Friday, January 18, at the time this article was filed, 10 new vulnerabilities have been reported. The site shows that XSS vulnerabilities have been reported many high-profile domains including yahoo.com, google.com, youtube.com, and msn.com, to name a few. Some of these flaws have been fixed; others apparently remain.

Some security experts consider XSS holes to be less significant than application or network vulnerabilities. But, as security researcher Russ McRee observes, e-commerce sites with XSS issues risk being out of compliance with Payment Card Industry data rules and losing the ability to accept credit cards online.