Security researchers fret over Adobe PDF flaw

Double danger

Adobe has warned that its Reader and Acrobat PDF software is vulnerable to an unpatched vulnerability.

A pair of flaws in the JavaScript functions of the PDF reading application are behind the problem, prompting Adobe to advise surfers to disable JavaScript as a workaround, pending the availability of a patch. Even after a patch becomes available, the problem may hang around for months. The vulnerability is a cross-platform flaw that affects Windows, Macs and Linux machines running Adobe's software.

The two security vulnerabilities in Adobe's software are particularly nasty, because they lend themselves to the planting of malicious code on vulnerable PCs. The flaws therefore potentially lend themselves to drive-by download attacks. There's no evidence of this happening as yet, even though proof of concept attack code has been developed.

Analysis on the response to the last such vulnerability from Adobe by security scanning firm Qualys, which dates back to February, shows that users were very slow at applying patches. Applying application security updates, as distinct from operating system patches, is becoming the most pressing problem in patching, according to Wolfgang Kandek, CTO at Qualys.

Security firms, such as Sophos and F-Secure (here), both advise surfers to consider the use of alternative PDF reader packages (list here), as a way of moving away from a monoculture of PDF readers, which is bad security practise. ®