Missing authorization in Mozilla Firefox
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-862.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 86
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Mozilla Firefox — GLSA-202104-10
12 records Highest priority Priority MEDIUM 2 MEDIUM, 10 LOW
Other records, highest priority first
- TI-2021-06299 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
- TI-2021-06293 One phishing tactic on the web is to provide a link with HTTP Auth.Priority MEDIUM 40
- TI-2021-06297 Clickjacking in Mozilla FirefoxPriority LOW 37
Timeline
- 2026-10-02 Threatist record created from CVE-2021-23975
- 2026-10-03 Alias added: GHSA-2r68-8x78-ffgh
References
More Mozilla Firefox vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2021-23975 · CVE Program
- CVE-2021-23975 · NVD
- FIRST EPSS
- GHSA-2r68-8x78-ffgh · GitHub Advisory Database · CC BY 4.0
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