A flaw was found in the way nodejs-tar, a Node.js module for reading and writing of tar archives, handled symbolic links when processing npm packages. An attacker could potentially use this flaw to rewrite arbitrary files on the system.
The fix normalizes symbolic links that point to targets outside the extraction root. This prevents packages containing symbolic links from overwriting targets outside the expected paths for a package.
Upstream announcement: https://github.com/npm/npm/releases/tag/v2.7.5
Upstream fix: https://github.com/npm/npm/commit/300834e91a4e2a95fb7fb59c309e7c3fc91d2312
Created nodejs-tar tracking bugs for this issue:
Affects: fedora-all [bug 1209503]
Affects: epel-all [bug 1209504]