Mikolaj Izdebski has discovered an integer overflow flaw in the BZ2_decompress function in bzip2/libbz2. An attacker could use a crafted bz2 file to cause a denial of service or potentially to execute arbitrary code. After the upgrade, all running services that use libbz2 need to be restarted. This update also provides rebuilt dpkg packages, which are statically linked to the fixed version of libbz2. Updated packages for clamav, which is also affected by this issue, will be provided on debian-volatile. For the stable distribution , these problems have been fixed in version 1.0.4-1+lenny1. For the testing distribution and the unstable distribution , this problem in bzip2 will be fixed soon. Updated dpkg packages are not necessary for testing/unstable. We recommend that you upgrade your bzip2 / dpkg packages.