4.3

CVE-2021-23969: debian debian_linux

CVSS: 4.3v3.1MediumModified
AliasesUBUNTU-CVE-2021-23969DEBIAN-CVE-2021-23969
Published 26-02-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-23969 is a medium (CVSS 4.3) vulnerability in debian debian_linux. EPSS estimates a 1.21% chance of exploitation in the next 30 days, higher than 68% 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
1.21%
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 26 · Related 12
DLA-2575-1DLA-2578-1DSA-4862-1DSA-4866-1MGASA-2021-0096MGASA-2021-0097

Timeline

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

Description

As specified in the W3C Content Security Policy draft, when creating a violation report, "User agents need to ensure that the source file is the URL requested by the page, pre-redirects. If that’s not possible, user agents need to strip the URL down to an origin to avoid unintentional leakage." Under certain types of redirects, Firefox incorrectly set the source file to be the destination of the redirects. This was fixed to be the redirect destination's origin. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

1.21%

Chance of exploitation in the next 30 days

Percentile

68%

Versus all other CVEs

30-day change

0.00 pp

From 1.21% on 20-09-2026

20-09-202620-10-2026
EPSS score
1.21%

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< 86.0+build3-0ubuntu0.16.04.1 | < 86.0+build3-0ubuntu0.18.04.1 | < 86.0+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)
Debian3 products
  • firefox-esr< 78.8.0esr-1
  • thunderbird< 1:78.8.0-1
  • debian_linuxEOL9.0 | 10.0
Mozilla3 products

3 vendors · 12 products

References

16 links
Show all 16 references