4.3

CVE-2021-23953: mozilla firefox

CVSS: 4.3v3.1MediumModified
AliasesUBUNTU-CVE-2021-23953DEBIAN-CVE-2021-23953
Published 26-02-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-23953 is a medium (CVSS 4.3) vulnerability in mozilla firefox. EPSS estimates a 1.06% chance of exploitation in the next 30 days, higher than 63.8% of scored vulnerabilities.

Overall risk
17/100
0100
Low · default modelHow is this calculated?
CVSS score
4.3/10
010
Medium · v3.1 (NVD)
EPSS score
1.06%
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 28 · Related 14
DLA-2539-1DLA-2541-1DSA-4840-1DSA-4842-1MGASA-2021-0065MGASA-2021-0066

Timeline

  1. 26-02-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

1.06%

Chance of exploitation in the next 30 days

Percentile

64%

Versus all other CVEs

30-day change

0.00 pp

From 1.06% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.06%

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

No weakness data has been published for this record.

Affected systems

Ubuntu6 products
  • firefox< 85.0+build1-0ubuntu0.16.04.1 | < 85.0+build1-0ubuntu0.18.04.1 | < 85.0+build1-0ubuntu0.20.04.1
  • mozjs38All versions (No fix recorded)
  • mozjs52All versions (No fix recorded)
  • mozjs68All versions (No fix recorded)
  • mozjs78All versions (No fix recorded)
Mozilla3 products
Debian2 products
  • firefox-esr< 78.7.0esr-1
  • thunderbird< 1:78.7.0-1

3 vendors · 11 products

References

11 links
Show all 11 references