libmspack: off-by-one error in the TOLOWER() macro for CHM decompression

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...

PT-2018-12658

Name of the Vulnerable Software and Affected Versions libmspack versions prior to 0.7alpha Description An issue was discovered in the CHM decompression functionality of libmspack, specifically in the mspack/chmd.c file. The problem lies in an off-by-one error within the TOLOWER macro...