CVE-2021-29971
9.8 · CRITICALOverview
CVE-2021-29971 is a critical-severity vulnerability affecting mozilla firefox. It was published on August 5, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
If a user had granted a permission to a webpage and saved that grant, any webpage running on the same host - irrespective of scheme or port - would be granted that permission. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 90.
Remediation
Check the references section for vendor advisories and patches from mozilla. Update firefox to the latest patched version. 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.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| mozilla | firefox | >= 0, < 90.0 | Affected |
Frequently Asked Questions
What is CVE-2021-29971?
CVE-2021-29971 is a critical-severity vulnerability affecting mozilla firefox. It was published on August 5, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2021-29971?
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-29971?
Check the references section for vendor advisories and patches from mozilla. Update firefox to the latest patched version. 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-2021-29971?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-29971 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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