Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a Directory Traversal vulnerability in gem installation that can result in the gem could write to arbitrary filesystem locations during installation. This attack appear to be exploitable via the victim must install a malicious gem. This vulnerability appears to have been fixed in 2.7.6.
CWE-22 - Path Traversal
Path traversal (or directory traversal), is a vulnerability that allows malicious users to traverse the server's root directory, gaining access to arbitrary files and folders such as application code & data, back-end credentials, and sensitive operating system files. In the worst-case scenario, an attacker could potentially execute arbitrary files on the server, resulting in a denial of service attack. Such an exploit may severely impact the integrity, confidentiality, and availability of an application.