CVE-2021-23975

MediumCVSS 6.5/10Last modified Jun 17, 2026

Description

The developer page about:memory has a Measure function for exploring what object types the browser has allocated and their sizes. When this function was invoked we incorrectly called the sizeof function, instead of using the API method that checks for invalid pointers. This vulnerability affects Firefox < 86.

Metrics

CVSS 3.1 6.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Weakness enumeration

CWE-862

Affected software

Vendor	Product	Versions
Mozilla	Firefox	< 86

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1685145Issue Tracking, Permissions Required, Vendor Advisory
https://security.gentoo.org/glsa/202104-10Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2021-07/Release Notes, Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1685145Issue Tracking, Permissions Required, Vendor Advisory
https://security.gentoo.org/glsa/202104-10Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2021-07/Release Notes, Vendor Advisory

Timeline

Published: Feb 26, 2021
Last modified: Jun 17, 2026
NVD status: Modified

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