Adobe Acrobat Reader is as close to ubiquitous as it comes. Most new Windows-based computers come with installed and many websites offer up documents in PDF format.

That makes Acrobat Reader a juicy target for hackers and a critical vulnerability has been discovered in Acrobat Reader versions 9 and earlier that could expose users to serious risk.

There are reports that exploits are already making the rounds and if these are accurate, which they appear to be, look out.

The vulnerability could be used to crash Acrobat Reader using what’s called a ‘buffer overflow‘ and these are the one of the worst kinds because they often give a hacker could take over a user’s computer entirely. That’s the case here.

Adobe says it will have a patch for Acrobat Reader 9 by March 11. Patches for earlier versions will follow.

Given how widely-used PDFs are, hopefully Adobe’s cooperation with anti-virus vendors will prevent a nightmare scenario from unfolding. As InfoWorld notes, this will probably lead to an increase in malicious PDFs.

Functionality and ubiquity always have their price.