This indicates an attack attempt to exploit a Buffer Overflow vulnerability in Adobe Acrobat and Reader.
The vulnerability is due to a lack boundary check conditions in the application when parsing PDF files in a malformed TrueTypeFont format. As a result, a remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted PDF file.
Adobe Reader X (10.1.2) and earlier 10.x versions for Windows and Macintosh
Adobe Reader 9.5 and earlier 9.x versions for Windows and Macintosh
Adobe Reader 9.4.6 and earlier 9.x versions for Linux
Adobe Acrobat X (10.1.2) and earlier 10.x versions for Windows and Macintosh
Adobe Acrobat 9.5 and earlier 9.x versions for Windows and Macintosh
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.