mspack/lzxd.c in libmspack 0.5alpha, as used in ClamAV 0.99.2, allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted CHM file.

Affected: Ubuntu:14.04:LTS: clamav, Ubuntu:16.04:LTS: clamav

It was discovered that ClamAV incorrectly handled parsing certain e-mail messages. A remote attacker could possibly use this issue to cause ClamAV to crash, resulting in a denial of service. (CVE-2017-6418)

It was discovered that ClamAV incorrectly handled certain malformed CHM files. A remote attacker could use this issue to cause ClamAV to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 14.04 LTS. In the default installation, attackers would be isolated by the ClamAV AppArmor profile. (CVE-2017-6419)

It was discovered that ClamAV incorrectly handled parsing certain PE files with WWPack compression. A remote attacker could possibly use this issue to cause ClamAV to crash, resulting in a denial of service. (CVE-2017-6420)