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. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-8872