Drew Yao discovered that libTIFF, a library for handling the Tagged Image File Format, is vulnerable to a programming error allowing malformed tiff files to lead to a crash or execution of arbitrary code.
For the stable distribution (etch), this problem has been fixed in version 3.8.2-7+etch1.
For the testing distribution (lenny), this problem has been fixed in version 3.8.2-10+lenny1.
The unstable distribution (sid) will be fixed soon.
We recommend that you upgrade your tiff package.
MD5 checksums of the listed files are available in the original advisory.