MEDIUM
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 Deserialization of Untrusted Data vulnerability in owner command that can result in code execution. This attack appear to be exploitable via victim must run the `gem owner` command on a gem with a specially crafted YAML file. This vulnerability appears to have been fixed in 2.7.6.
http://blog.rubygems.org/2018/02/15/2.7.6-released.html
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html
https://access.redhat.com/errata/RHSA-2018:3729
https://access.redhat.com/errata/RHSA-2018:3730
https://access.redhat.com/errata/RHSA-2018:3731
https://access.redhat.com/errata/RHSA-2019:2028
https://github.com/rubygems/rubygems/commit/254e3d0ee873c008c0b74e8b8abcbdab4caa0a6d
https://lists.debian.org/debian-lts-announce/2018/04/msg00017.html
https://lists.debian.org/debian-lts-announce/2018/08/msg00028.html
https://lists.debian.org/debian-lts-announce/2019/05/msg00028.html
https://usn.ubuntu.com/3621-1/
https://usn.ubuntu.com/3621-2/
https://usn.ubuntu.com/3685-1/
Source: MITRE
Published: 2018-03-13
Updated: 2019-05-20
Type: CWE-502
Base Score: 6.8
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 7.8
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 1.8
Severity: HIGH