Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 allows code injection if the first argument (aka the "command" argument) to Shell#] or Shell#test in lib/shell.rb is untrusted data. An attacker can exploit this to call an arbitrary Ruby method. CREATE(Triage):(User=admin) [CVE-2019-16255 (https://nvd.nist.gov/vuln/detail/CVE-2019-16255)