The set_fat function in fat.c in dosfstools before 4.0 might allow attackers to corrupt a FAT12 filesystem or cause a denial of service (invalid memory read and crash) by writing an odd number of clusters to the third to last entry on a FAT12 filesystem, which triggers an “off-by-two error.”
lists.opensuse.org/opensuse-updates/2016-06/msg00001.html
lists.opensuse.org/opensuse-updates/2016-09/msg00014.html
www.securityfocus.com/bid/90311
www.ubuntu.com/usn/USN-2986-1
blog.fuzzing-project.org/44-dosfstools-fsck.vfat-Several-invalid-memory-accesses.html
github.com/dosfstools/dosfstools/commit/07908124838afcc99c577d1d3e84cef2dbd39cb7
github.com/dosfstools/dosfstools/issues/12
github.com/dosfstools/dosfstools/releases/tag/v4.0
lists.debian.org/debian-lts-announce/2020/05/msg00028.html