Updated: A QuickTime bug can be used to gain access to Firefox, IE, Skype and other programs, a researcher says.A researcher has shown that a low-risk, year-old QuickTime bug can easily be turned into a high-risk attack on Firefox, Internet Explorer, Skype and other programs.
The researcher, Petko D. Petkov—aka pdp—on Sept. 12 posted proof-of-concept code showing how QuickTime media formats can be used to get into Firefox, leading to full browser compromise and perhaps even to compromise of the underlying operating system. QuickTime comes by default with iTunes, Petkov noted. "Therefore, iTunes users are most affected," he said.
Petkov has been trying to get people to pay attention to a duo of QuickTime flaws since September 2006, when he demonstrated how to use QuickTime Movie files to trick users into executing malicious JavaScript code. The technique doesnt rely on a vulnerability; rather, its caused by what Petkov said is an insecure feature that first appeared in QuickTime 3 and continues on up to Version 7.
Click here to read more about how QuickTime movies are a vector for system hijacks.
In December 2006, he pointed out that a semi-automatic worm that hit MySpace was propagating via the same QuickTime flaw.
The problem that still remains to be patched has to do with the versatile nature of QuickTime, used in iTunes. QuickTime supports a wide host of media formats. Because of this flexibility, Petkov said, QuickTime allows execution of malicious content in JavaScript form as delivered by media files including MP3, MP4, M4A, and "everything else that is supported," he said in his September 2006 warning.
Although users can only get to the audio and video formats, malicious code can be pasted into files with an extension list of extensions: .3g2, .3gp, .3gp2, .3gpp, .amr, .aac, .adts, .aif, .aifc, .aiff, .amc, .au, .avi, .bwf, .caf, .cdda, .cel, .flc, .fli, .gsm, .m15, .m1a, .m1s, .m1v, .m2a, .m4a, .m4b, .m4p, .m4v, .m75, .mac, .mov, .mp2, .mp3, .mp4, .mpa, .mpeg, .mpg, .mpm, .mpv, .mqv, .pct, .pic, .pict, .png, .pnt, .pntg, .qcp, .qt, .qti, .qtif, .rgb, .rts, .rtsp, .sdp, .sdv, .sgi, .snd, .ulw, .vfw, .wav and others, Petkov said.
The exploit then gives an attacker the ability to do anything with the browser, he said, including installing backdoors, or grants access to the operating system if the victim is running with administrative privileges.
Petkov told eWEEK in an e-mail exchange that one of the best ways for Firefox users to protect themselves is to install the NoScript Firefox extension. NoScript allows JavaScript, Java and other executable content to run only from trusted domains of the users choice and guards the "trust boundaries" against XSS (cross-site scripting) attacks. Another way for users to protect themselves is to simply uninstall or disable QuickTime runtime, he said.
"The first method is a lot faster and more transparent to the user," he said, but its only Firefox-specific. The technique used for Petkovs proof of concept can be applied to Internet Explorer, Skype and any other application that has protocol handlers associated with the underlying system, he told eWEEK.
Mozillas security chief Window Snyder wrote in a post later in the evening Sept. 12 that "Mozilla is working with Apple to keep our users safe and we are also investigating ways to mitigate this more broadly in Firefox."
A spokesperson for Apple said the company had no response for this vulnerability but said, "Apple takes security very seriously and has a great track record of addressing potential vulnerabilities before they can affect users."
Editors Note: This story was updated to include additional information and comments from Petkov, as well as a comment from an Apple spokesperson.
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