Security gone awry: IE 8 XSS filter exposes sites to XSS attacks
The cross-site scripting filter that ships with Microsoft’s Internet Explorer 8 browser can be abused by attackers to launch cross-site scripting attacks on websites and web pages that would otherwise be immune to this threat.
According to a presentation
at this year’s Black Hat Europe conference, the issue introduces security problems at several high-profile websites, including Microsoft’s own Bing.com (screenshot
), Google.com, Wikipedia.org, Twitter.com (screenshot
) and just about any site that lets IE 8 users create profiles.
Microsoft added the anti-XSS feature in IE 8 last August to detect Type-1 (reflection) attacks that can lead to cookie theft, keystroke logging, Web site defacement and credentials theft. However, as the researchers discovered, Microsoft’s filters work by scanning outbound requests for string that may be malicious.