An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links. This could have led to security issues for websites relying on sandbox configurations that allowed popups and hosted arbitrary content. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00025.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1521542
https://usn.ubuntu.com/4443-1/
https://www.mozilla.org/security/advisories/mfsa2020-30/
Source: MITRE
Published: 2020-08-10
Updated: 2020-08-18
Type: NVD-CWE-Other
Base Score: 4.3
Vector: AV:N/AC:M/Au:N/C:N/I:P/A:N
Impact Score: 2.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 6.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Impact Score: 3.6
Exploitability Score: 2.8
Severity: MEDIUM