CVE-2021-23986

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.

Weakness

The product does not properly verify that the source of data or communication is valid.

Affected Software

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/111.html
• https://cwe.mitre.org/data/definitions/141.html
• https://cwe.mitre.org/data/definitions/142.html
• https://cwe.mitre.org/data/definitions/160.html
• https://cwe.mitre.org/data/definitions/21.html
• https://cwe.mitre.org/data/definitions/384.html
• https://cwe.mitre.org/data/definitions/385.html
• https://cwe.mitre.org/data/definitions/386.html
• https://cwe.mitre.org/data/definitions/387.html
• https://cwe.mitre.org/data/definitions/388.html
• https://cwe.mitre.org/data/definitions/510.html
• https://cwe.mitre.org/data/definitions/59.html
• https://cwe.mitre.org/data/definitions/60.html
• https://cwe.mitre.org/data/definitions/75.html
• https://cwe.mitre.org/data/definitions/76.html
• https://cwe.mitre.org/data/definitions/89.html

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1692623
• https://www.mozilla.org/security/advisories/mfsa2021-10/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1692623
• https://www.mozilla.org/security/advisories/mfsa2021-10/