CVE-2021-29964
A locally-installed hostile program could send `WM_COPYDATA` messages that Firefox would process incorrectly, leading to an out-of-bounds read. *This bug only affects Firefox on Windows. Other
02 Description
A locally-installed hostile program could send `WM_COPYDATA` messages that Firefox would process incorrectly, leading to an out-of-bounds read. *This bug only affects Firefox on Windows. Other
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 0.81% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 56.8% of scored records. A rank, not a probability.
- NVD base score
- 7.1 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-06-24 13:15Z5 YR AGO
- Last updated
- 2024-08-03 22:24Z2 YR AGO
- Reserved
- 2021-04-01
- Assigning CNA
- mozilla
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-125Out-of-bounds ReadBase
- Data version
- 5.1
- Document digest
- f02255b5fd3ad213cad5927d4619a9535094504b5e20d1f82f76fcd4b55fda14
05 Affected products
06 References
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-26/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-24/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-23/
- bugzilla.mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=1706501
07 Fixed in
Arch Linux
- firefox Not affected
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- mozjs38 No fix yet
- mozjs52 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- mozjs52 No fix yet
- mozjs68 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- mozjs78 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.