Adobe's PSIRT (Product Security Incident Response Team) published a new blog post today [1]. The post reveals that a critical vulnerability, CVE-2009-3459, is now being exploited in the wild in targeted attacks. The vulnerability affects Adobe 9.1.3 on Windows, Unix and OS X. However, the exploits have been limited to Windows so far.

An update scheduled to be released on Oct 13th should fix the problem. Until then, Windows users are advised to enable DEP. Anti malware vendors have been informed by Adobe.

This vulnerability does not require Javascript. If you disabled Javascript in the past, it will not protect you in this case. Another workaround I found helpful: You can "clean" PDF documents by first converting them into another format (like Postscript) and then back into PDF. However, this is not 100% certain to remove the exploit and you may infect the machine that does the conversion as it will likely still use the vulnerable libraries to convert the document. But the likelyhood of this happening is quite low.

[1] http://blogs.adobe.com/psirt/2009/10/adobe_reader_and_acrobat_issue_1.html

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Johannes B. Ullrich, Ph.D.
SANS Technology Institute
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