Updated at 3:37 p.m. PST with statement from MySpace and Facebook.
Within the last week, researcher Elazar Broad has disclosed two ActiveX vulnerabilities in the tools that MySpace.com and Facebook users use to upload images to their sites. On Sunday, Broad disclosed a buffer overflow vulnerability within the Facebook image upload control. Last week, Broad disclosed a similar buffer overflow flaw within MySpaceAurigma's ImageUploader ActiveX; the MySpace vulnerability also affects Facebook users.
Facebook and MySpace use controls repackaged from Aurigma Imaging Technology. Vulnerable to the recent attack scenario are FaceBook PhotoUploader 188.8.131.52, Aurigma ImageUploader4 184.108.40.206, Aurigma ImageUploader4 220.127.116.11, Aurigma ImageUploader4 18.104.22.168, and Aurigma ImageUploader5 22.214.171.124.
The MySpace attack outlined last week could allow specially crafted Web pages to crash Windows systems. The Facebook attack announced Sunday could allow for denial-of-service attacks or for malicious code to run on compromised PCs. An exploit exists for the MySpace attack. An exploit for the Facebook attack is expected to be posted on the Internet shortly.
Recent versions of Facebook PhotoUploader 126.96.36.199 are not vulnerable. Also, for the MySpace vulnerability, Aurigma Imaging Technology recommends upgrading to the latest 4.x and 5.x releases.
Additional workarounds include disabling all ActiveX within Internet Explorer. Microsoft provides detailed instructions here. You can also disable just the image uploader within either Facebook or MySpace.
On Monday afternoon, MySpace and Facebook issued a joint statement: "MySpace and Facebook are firmly committed to keeping all users as safe and secure as possible. Recently, the companies were alerted to a vulnerability in Aurigma Imaging Technology's software that could potentially put certain users with Windows-based systems at risk. Immediately after identifying a solution, Facebook, MySpace, and Aurigma collaborated to resolve the issue and are working to individually alert users of any additional steps that need to be taken to ensure user security."