8.8

CVE-2021-38495: mozilla firefox_esr Out-of-bounds Write

CVSS: 8.8v3.1HighModified
AliasesUBUNTU-CVE-2021-38495
Published 03-11-2021Last modified 04-08-2024
Open JSON

Vulnerability summary

CVE-2021-38495 is a high (CVSS 8.8) Out-of-bounds Write vulnerability in mozilla firefox_esr. EPSS estimates a 1.11% chance of exploitation in the next 30 days, higher than 65.3% 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
1.11%
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 15 · Related 15
OPENSUSE-SU-2021:1367-1OPENSUSE-SU-2021:1635-1OPENSUSE-SU-2021:3331-1OPENSUSE-SU-2021:3451-1OPENSUSE-SU-2021:4150-1OPENSUSE-SU-2024:10601-1

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 Thunderbird 78.13.0. 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 Thunderbird < 91.1 and Firefox ESR < 91.1.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.11%

Chance of exploitation in the next 30 days

Percentile

65%

Versus all other CVEs

30-day change

0.00 pp

From 1.11% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.11%

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

Mozilla2 products
Ubuntu1 product
  • thunderbird< 1:91.5.0+build1-0ubuntu0.18.04.1 | < 1:91.5.0+build1-0ubuntu0.20.04.1

2 vendors · 3 products

References

9 links