The TIFFExtractData macro in LibTIFF before 3.9.4 does not properly
handle unknown tag types in TIFF directory entries, which allows
remote attackers to cause a denial of service (out-of-bounds read and
application crash) via a crafted TIFF file.
According to Dan Rosenberg's report, this was originally reported to iDefense. Dan did not publish too much details about this issue, as it's addressed by Tom's patch from upstream bug report #2210.
This issue has been addressed in following products:
Red Hat Enterprise Linux 4
Red Hat Enterprise Linux 5
Via RHSA-2010:0519 https://rhn.redhat.com/errata/RHSA-2010-0519.html