CVE-2021-38492: mozilla firefox
Vulnerability summary
CVE-2021-38492 is a medium (CVSS 6.5) vulnerability in mozilla firefox. EPSS estimates a 1.16% chance of exploitation in the next 30 days, higher than 66.7% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 16 · Related 16Timeline
- 03-11-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
When delegating navigations to the operating system, Firefox would accept the `mk` scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. *This bug only affects Firefox for Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 92, Thunderbird < 91.1, Thunderbird < 78.14, Firefox ESR < 78.14, and Firefox ESR < 91.1.
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS trend
Probability
1.16%
Chance of exploitation in the next 30 days
Percentile
67%
Versus all other CVEs
30-day change
0.00 pp
From 1.16% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (bugzilla.mozilla.org)
Maturity: unknown
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu4 products
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
- mozjs78All versions (No fix recorded)
Mozilla3 products
- firefox≥ unspecified, < 92 | < 92.0 | ≥ 91.0, < 91.1
- firefox_esr≥ unspecified, < 78.14 | ≥ unspecified, < 91.1 | < 78.14
- thunderbird≥ unspecified, < 91.1 | ≥ unspecified, < 78.14 | < 78.14 | ≥ 91.0, < 91.1
2 vendors · 7 products