This indicates an attack attempt against an integer-overflow vulnerability in Xpdf.
The vulnerability is caused by an error when the vulnerable software handles a specially crafted PDF document. It allows a remote attacker to cause a denial of service (application crash) or possibly execute arbitrary code.
Affected Products
Xpdf Xpdf 3.0 pl3 and previous versions
Recommended Actions
Apply the patch available at the following website: ftp://ftp.foolabs.com/pub/xpdf/xpdf-3.02pl4.patch