CVE-2021-29952

Description

When Web Render components were destructed, a race condition could have caused undefined behavior, and we presume that with enough effort may have been exploitable to run arbitrary code. This vulnerability affects Firefox < 88.0.1 and Firefox for Android < 88.1.3.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.25%
Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: Mozilla Firefox
Affected: Mozilla Firefox for Android
Published at:
Updated at:

References

Link Tags
https://www.mozilla.org/security/advisories/mfsa2021-20/ release notes vendor advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1704227 vendor advisory permissions required

Frequently Asked Questions

What is the severity of CVE-2021-29952?
CVE-2021-29952 has been scored as a high severity vulnerability.
How to fix CVE-2021-29952?
To fix CVE-2021-29952, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-29952 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-29952 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-29952?
CVE-2021-29952 affects Mozilla Firefox, Mozilla Firefox for Android.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.