7.1

CVE-2021-29964: mozilla firefox Out-of-bounds Read

CVSS: 7.1v3.1HighModified
AliasesUBUNTU-CVE-2021-29964
Published 24-06-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-29964 is a high (CVSS 7.1) Out-of-bounds Read vulnerability in mozilla firefox. EPSS estimates a 0.82% chance of exploitation in the next 30 days, higher than 56.3% of scored vulnerabilities.

Overall risk
29/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.1/10
010
High · v3.1 (NVD)
EPSS score
0.82%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 13 · Related 12
MGASA-2021-0242OPENSUSE-SU-2021:0858-1OPENSUSE-SU-2021:0910-1OPENSUSE-SU-2021:1884-1OPENSUSE-SU-2021:2003-1OPENSUSE-SU-2024:10600-1

Timeline

  1. 24-06-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

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 operating systems are unaffected.*. This vulnerability affects Thunderbird < 78.11, Firefox < 89, and Firefox ESR < 78.11.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.82%

Chance of exploitation in the next 30 days

Percentile

56%

Versus all other CVEs

30-day change

0.00 pp

From 0.82% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.82%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu4 products
  • mozjs38All versions (No fix recorded)
  • mozjs52All versions (No fix recorded)
  • mozjs68All versions (No fix recorded)
  • mozjs78All versions (No fix recorded)
Mozilla3 products

2 vendors · 7 products

References

8 links