bzlib.c in bzip2 before 1.0.5 allows user-assisted remote attackers to cause a denial of service (crash) via a crafted file that triggers a buffer over-read, as demonstrated by the PROTOS GENOME test suite for Archive Formats.
A bzip2 security issue was reported to Debian security team:
Mikołaj Izdebski has discovered an integer overflow flaw in the BZ2decompress function in bzip2/libbz2. An attacker could use a crafted bz2 file to cause a denial of service (application crash) or potentially to execute arbitrary code. (CVE-2010-0405)