Chris Evans discovered several security related problems in libungif4, a shared library for GIF images. The Common Vulnerabilities and Exposures project identifies the following vulnerabilities:
Null pointer dereference, that could cause a denial of service.
Out of bounds memory access that could cause a denial of service or the execution of arbitrary code.
For the old stable distribution (woody) these problems have been fixed in version 4.1.0b1-2woody1.
For the stable distribution (sarge) these problems have been fixed in version 4.1.3-2sarge1.
For the unstable distribution (sid) these problems will be fixed soon.
We recommend that you upgrade your libungif4 packages.
MD5 checksums of the listed files are available in the original advisory.