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CVE-2021-23986

6.5 · MEDIUM

A malicious extension with the 'search' permission could have installed a new search engine whose favicon referenced a cross-origin URL.

Published Mar 31, 2021CWE-346EPSS 0.43%

Overview

CVE-2021-23986 is a medium-severity vulnerability. It was published on March 31, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).

This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical 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.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refbugzilla.mozilla.org/show_bug.cgi?id=1692623Refwww.mozilla.org/security/advisories/mfsa2021-10/Refbugzilla.mozilla.org/show_bug.cgi?id=1692623Refwww.mozilla.org/security/advisories/mfsa2021-10/

How CyberStrike helps

Frequently asked questions

What is CVE-2021-23986?

CVE-2021-23986 is a medium-severity vulnerability. It was published on March 31, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2021-23986?

This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2021-23986?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2021-23986?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2021-23986 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

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