fstream before 1.0.12 is vulnerable to Arbitrary File Overwrite. Extracting tarballs containing a hardlink to a file that already exists in the system, and a file that matches the hardlink, will overwrite the system's file with the contents of the extracted file. The fstream.DirWriter() function is vulnerable.
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00052.html
https://github.com/npm/fstream/commit/6a77d2fa6e1462693cf8e46f930da96ec1b0bb22