The Shadowserver Foundation has recently become aware of a very severe vulnerability in Adobe Acrobat affecting versions 8.x and 9 that is currently on the loose in the wild and being actively exploited. We are aware of several different variations of this attack, however, we were provided with a sample last week in which we were permitted to analyze and detail in this post. We want to make it clear that we did not discover this vulnerability and are only posting this information to make sure others are aware and can adequately protect themselves. All of our testing was done on Adobe Acrobat Reader 8.1.0, 8.1.1, 8.1.2, 8.1.3 (latest release of 8), and 9.0.0 (latest release of 9). We have not confirmed via testing that the exploit actually works on Adobe Acrobat (non-Reader) but believe that it will also affect it as well.
Right now we believe these files are only being used in a smaller set of targeted attacks. However, these types of attacks are frequently the most damaging and it is only a matter of time before this exploit ends up in every exploit pack on the Internet. As a result we are also not going to provide any specific details on how the exploit works despite the fact that information is known.
Adobe has since issued a public advisory about this issue that has been posted here. They are expecting an update by March 11th, 2009 for Adobe 9 and updates for other version (8 and 7) to follow soon after. We have also received some other feedback and information that may be useful that we will post in the near future.