Some vulnerabilities have been reported in LibTIFF, which can be exploited by malicious people to potentially compromise an application using the library.

1) A boundary error within the "EXPAND2D()" macro in libtiff/tif_fax3.h when decoding CCITT Group 4 compressed TIFF images can be exploited to cause a heap-based buffer overflow via specially crafted TIFF images.

Successful exploitation may allow execution of arbitrary code.

2) A boundary error within the ThunderScan decoder when processing images with an incorrect number of bitspersample can be exploited to cause a heap-based buffer overflow via specially crafted ThunderScan encoded files.

3) An error within the handling of certain TIFF files can be exploited to cause a memory corruption by tricking a user into opening a specially crafted TIFF file.

4) An error within the "OJPEGReadHeaderInfoSecStreamSof()" function in libtiff/tif_ojpeg.c can be exploited to cause a memory corruption by tricking a user into opening a specially crafted TIFF file.

5) An integer overflow error exists within the "tiffdump" utility, which can be exploited by e.g. tricking a user into opening a specially crafted TIFF file containing a directory with a large item count.

Solution
Update to version 3.9.5.

Provided and/or discovered by
1) Apple Product Security
2) Martin Barbella via ZDI
3) Tom Lane and Robert Swiecki
4) Tavis Ormandy
5) Tom Lane

Changelog
Further details available to Secunia VIM customers

Original Advisory
APPLE-SA-2011-03-02-1:
http://lists.apple.com/archives/security-announce/2011/Mar/msg00000.html

LibTIFF:
http://www.remotesensing.org/libtiff/v3.9.5.html
http://bugzilla.maptools.org/show_bug.cgi?id=1999
http://bugzilla.maptools.org/show_bug.cgi?id=2140
http://bugzilla.maptools.org/show_bug.cgi?id=2218
http://bugzilla.maptools.org/show_bug.cgi?id=2228
http://bugzilla.maptools.org/show_bug.cgi?id=2300

ZDI-11-107:
http://www.zerodayinitiative.com/advisories/ZDI-11-107/

Technical Analysis
Further details available to Secunia VIM customers

Alternate/detailed remediation
Further details available in Customer Area

Deep Links
Links available to Secunia VIM customers