An issue was discovered in mspack/chmd.c in libmspack before 0.7alpha. There is an off-by-one error in the TOLOWER() macro for CHM decompression.Referenceshttps://usn.ubuntu.com/3728-3/https://www.debian.org/security/2018/dsa-4260https://lists.debian.org/debian-lts-announce/2018/08/msg00007.htmlhttps://bugs.debian.org/904800http://www.openwall.com/lists/oss-security/2018/07/26/1https://access.redhat.com/errata/RHSA-2018:3505https://usn.ubuntu.com/3789-2/https://usn.ubuntu.com/3728-2/http://www.securitytracker.com/id/1041410https://github.com/kyz/libmspack/commit/4fd9ccaa54e1aebde1e4b95fb0163b699fd7bcc8https://usn.ubuntu.com/3728-1/https://access.redhat.com/errata/RHSA-2018:3327https://security.gentoo.org/glsa/201903-20
