Vulnerability Description
A malicious extension with the 'search' permission could have installed a new search engine whose favicon referenced a cross-origin URL. The response to this cross-origin request could have been read by the extension, allowing a same-origin policy bypass by the extension, which should not have cross-origin permissions. This cross-origin request was made without cookies, so the sensitive information disclosed by the violation was limited to local-network resources or resources that perform IP-based authentication. This vulnerability affects Firefox < 87.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 87.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1692623Issue TrackingPermissions RequiredVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-10/Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1692623Issue TrackingPermissions RequiredVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-10/Vendor Advisory
FAQ
What is CVE-2021-23986?
CVE-2021-23986 is a vulnerability with a CVSS score of 6.5 (MEDIUM). A malicious extension with the 'search' permission could have installed a new search engine whose favicon referenced a cross-origin URL. The response to this cross-origin request could have been read ...
How severe is CVE-2021-23986?
CVE-2021-23986 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-23986?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox.