Integer underflow in the cli_scanpe function in pe.c in ClamAV before 0.97.8 allows remote attackers to cause a denial of service (crash) via a skewed offset larger than the size of the PE section in a UPX packed executable, which triggers an out-of-bounds read.

The bytecode engine in ClamAV before 0.97.3 allows remote attackers to cause a denial of service (crash) via vectors related to "recursion level" and (1) libclamav/bytecode.c and (2) libclamav/bytecode_api.c.

Off-by-one error in the cli_hm_scan function in matcher-hash.c in libclamav in ClamAV before 0.97.2 allows remote attackers to cause a denial of service (daemon crash) via an e-mail message that is not properly handled during certain hash calculations.