Auth bypass in Mozilla Firefox

CVE-2020-15664

By holding a reference to the eval() function from an about:blank window, a malicious webpage could have gained access to the InstallTrigger object which would allow them to prompt the user to install an extension. Combined with user confusion, this could result in an unintended or malicious extension being installed. This vulnerability affects Firefox < 80, Thunderbird < 78.2, Thunderbird < 68.12, Firefox ESR < 68.12, Firefox ESR < 78.2, and Firefox for Android < 80.

Vulnerability class: Broken Access Control

EPSS: 0.014 (69.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-15664?
CVE-2020-15664 is a medium-severity vulnerability in Mozilla Firefox, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2020-10-01.
How severe is CVE-2020-15664?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2020-15664 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.