Rebar3 versions 3.0.0-beta.3 to 3.13.2 are vulnerable to OS command injection via URL parameter of dependency specification.
https://vuln.be/post/rebar3-command-injection/
https://github.com/vulnbe/poc-rebar3.git
http://packetstormsecurity.com/files/159027/Rebar3-3.13.2-Command-Injection.html