CVE-2021-4128 json
When transitioning in and out of fullscreen mode, a graphics object was not correctly protected; resulting in memory corruption and a poten…
published 2022-12-22 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34002
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 47%
- public exploits
- 0
- none known
Summary
When transitioning in and out of fullscreen mode, a graphics object was not correctly protected; resulting in memory corruption and a potentially exploitable crash.<br>*This bug only affects Firefox on MacOS. Other operating systems are unaffected.*. This vulnerability affects Firefox < 95.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 18 mo ago
Exploit prediction
0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1735852 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
Affected products
- Mozilla Firefox
Classification
- Weakness
-
- CWE-416 Use After Free
References
-
bugzilla.mozilla.org
/show_bug.cgi?id=1735852
exploit, issue-tracking, patch, vendor-advisory
-
mozilla.org
/security/advisories/mfsa2021-52/
vendor-advisory
Sources
- CVE List CVE-2021-4128
- NVD CVE-2021-4128
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.