8.8

CVE-2021-23997: mozilla firefox

CVSS: 8.8v3.1HighModified
AliasesUBUNTU-CVE-2021-23997
Published 24-06-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-23997 is a high (CVSS 8.8) 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
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
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 3 · Related 3
OPENSUSE-SU-2024:10600-1OPENSUSE-SU-2024:14572-1USN-4926-1

Timeline

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

Description

Due to unexpected data type conversions, a use-after-free could have occurred when interacting with the font cache. We presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox < 88.

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

Ubuntu5 products
  • firefox< 88.0+build2-0ubuntu0.16.04.1 | < 88.0+build2-0ubuntu0.18.04.2 | < 88.0+build2-0ubuntu0.20.04.1
  • mozjs38All versions (No fix recorded)
  • mozjs52All versions (No fix recorded)
  • mozjs68All versions (No fix recorded)
  • mozjs78All versions (No fix recorded)
Mozilla1 product
  • firefox≥ unspecified, < 88 | < 88.0

2 vendors · 6 products

References

6 links