CVE-2021-21815 — Out-of-bounds Write in Xmill

A stack-based buffer overflow vulnerability exists in the command-line-parsing HandleFileArg functionality of AT&T Labs' Xmill 0.7. Within the function HandleFileArg the argument filepattern is under control of the user who passes it in from the command line. filepattern is passed directly to strcpy copying the path provided by the user into a staticly sized buffer without any length checks resulting in a stack-buffer overflow. An attacker can provide malicious input to trigger this vulnerabilit…