8.8

CVE-2021-38493: mozilla firefox Out-of-bounds Write

CVSS: 8.8v3.1HighModified
AliasesMGASA-2021-0425MGASA-2021-0427RHSA-2021:3494
Published 03-11-2021Last modified 04-08-2024
Open JSON

Vulnerability summary

CVE-2021-38493 is a high (CVSS 8.8) Out-of-bounds Write vulnerability in mozilla firefox. EPSS estimates a 1.24% chance of exploitation in the next 30 days, higher than 69% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
010
High · v3.1 (NVD)
EPSS score
1.24%
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 6 · Related 6
OPENSUSE-SU-2021:1635-1OPENSUSE-SU-2021:4150-1OPENSUSE-SU-2024:10600-1OPENSUSE-SU-2024:14572-1SUSE-SU-2021:4150-1USN-5074-1

Timeline

  1. 03-11-2021
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

Mozilla developers reported memory safety bugs present in Firefox 91 and Firefox ESR 78.13. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.14, Thunderbird < 78.14, and Firefox < 92.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

1.24%

Chance of exploitation in the next 30 days

Percentile

69%

Versus all other CVEs

30-day change

0.00 pp

From 1.24% on 21-09-2026

21-09-202621-10-2026
EPSS score
1.24%

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

Redhat6 products
  • firefox< 0:78.14.0-1.el8_2 | < 0:78.14.0-1.el8_4 | < 0:78.14.0-1.el7_9 | < 0:78.14.0-1.el8_1
  • firefox-debuginfo< 0:78.14.0-1.el8_2 | < 0:78.14.0-1.el8_4 | < 0:78.14.0-1.el7_9 | < 0:78.14.0-1.el8_1
  • firefox-debugsource< 0:78.14.0-1.el8_2 | < 0:78.14.0-1.el8_4 | < 0:78.14.0-1.el8_1
  • thunderbird< 0:78.14.0-1.el7_9 | < 0:78.14.0-1.el8_1 | < 0:78.14.0-1.el8_4 | < 0:78.14.0-1.el8_2
  • thunderbird-debuginfo< 0:78.14.0-1.el7_9 | < 0:78.14.0-1.el8_1 | < 0:78.14.0-1.el8_4 | < 0:78.14.0-1.el8_2
Ubuntu6 products
  • firefox< 92.0+build3-0ubuntu0.18.04.1 | < 92.0+build3-0ubuntu0.20.04.1
  • mozjs38All versions (No fix recorded)
  • mozjs52All versions (No fix recorded)
  • mozjs68All versions (No fix recorded)
  • mozjs78All versions (No fix recorded)
Mageia5 products
  • firefox< 91.1.0-1.mga8
  • firefox-l10n< 91.1.0-1.mga8
  • nss< 3.70.0-1.mga8
  • thunderbird< 91.1.1-1.mga8
  • thunderbird-l10n< 91.1.1-1.mga8
Mozilla3 products
Debian2 products
  • firefox-esr< 78.14.0esr-1~deb10u1 | < 78.14.0esr-1~deb11u1 | < 78.14.0esr-1~deb9u1 | < 78.14.0esr-1
  • thunderbird< 1:78.14.0-1~deb10u1 | < 1:78.14.0-1~deb11u1 | < 1:78.14.0-1~deb9u1 | < 1:78.14.0-1

5 vendors · 22 products

References

52 links
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