CVE-2021-38494: mozilla firefox Out-of-bounds Write
Modified
AliasesUBUNTU-CVE-2021-38494
Published 03-11-2021Last modified 04-08-2024
Vulnerability summary
CVE-2021-38494 is a high (CVSS 8.8) Out-of-bounds Write vulnerability in mozilla firefox. EPSS estimates a 0.81% chance of exploitation in the next 30 days, higher than 56.3% of scored vulnerabilities.
CVSS score
8.8/10
010
High · v3.1 (NVD)EPSS score
0.81%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 3 · Related 3Timeline
- 03-11-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
Mozilla developers reported memory safety bugs present in Firefox 91. 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 Firefox < 92.
CVSS metrics
3 scores · 2 sources · 2 versionsHigh 8.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 2 agree
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Medium 6.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
0.81%
Chance of exploitation in the next 30 days
Percentile
56%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.81% on 22-09-2026
22-09-202622-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu5 products
- firefox< 92.0+build3-0ubuntu0.18.04.1 | < 92.0+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)
Mozilla1 product
- firefox≥ unspecified, < 92 | < 92.0
2 vendors · 6 products