Adobe slates patch for Flash clipboard poisoning attacks

Computerworld - Adobe Systems Inc. last week said it will soon quash a bug in Flash that has been used for more than a month by attackers to poison Macintosh and Windows users' clipboards with URLs to malicious sites.

The changes will be rolled out in Flash 10, which Adobe security program manager David Lenoe said would be released "soon." A release candidate for Flash 10, however, that includes the patch can be downloaded now.

In August, security researchers reported malicious scripts in Flash-based ads on legitimate sites. The scripts abused the "setClipboard" command in Flash to repeatedly infect users' clipboards with URLs pushing fake security software. The scammers hoped that some users would paste the URL into their browsers' address bars and would be duped into purchasing the bogus program once at the phony software site.

Users on several message boards, including Apple Inc.'s support forum, reported the clipboard poisoning more than a month ago.

Lenoe acknowledged the attacks in an Aug. 19 post to Adobe's security response team's blog but at the time said only that the company was investigating "potential solutions." Adobe, however, has not patched the current production version of Flash 9.

On Friday, Lenoe pointed users to a description of the security changes being implemented in Flash 10. Among the changes, said Adobe developer Trevor McCauley, was one that will lock down the setClipboard command to prevent automated abuses. In Flash 10, the setClipboard command can be called up only through some kind of user-initiated action, such as clicking the mouse or typing on the keyboard. Remote calls of the command will be disallowed.

Adobe first unveiled a beta of Flash 10 in May and shifted to a more polished release candidate a week ago. Flash 10 can be downloaded in its current form from Adobe's site.

According to Adobe, the security changes that McCauley outlined have been integrated into Flash 10's release candidate.

Read more about security in Computerworld's Security Knowledge Center.