CVE-2021-23954: mozilla firefox Type Confusion
CVSS: 8.8v3.1HighModified
AliasesUBUNTU-CVE-2021-23954DEBIAN-CVE-2021-23954
Published 26-02-2021Last modified 03-08-2024
Vulnerability summary
CVE-2021-23954 is a high (CVSS 8.8) Type Confusion vulnerability in mozilla firefox. EPSS estimates a 1.19% chance of exploitation in the next 30 days, higher than 67.3% of scored vulnerabilities.
CVSS score
8.8/10
010
High · v3.1 (NVD)EPSS score
1.19%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 28 · Related 14DLA-2539-1DLA-2541-1DSA-4840-1DSA-4842-1MGASA-2021-0065MGASA-2021-0066OPENSUSE-SU-2021:0208-1OPENSUSE-SU-2021:0209-1OPENSUSE-SU-2021:0222-1OPENSUSE-SU-2021:0223-1OPENSUSE-SU-2024:10600-1OPENSUSE-SU-2024:10601-1OPENSUSE-SU-2024:14572-1RHSA-2021:0285RHSA-2021:0288RHSA-2021:0289RHSA-2021:0290RHSA-2021:0297RHSA-2021:0298RHSA-2021:0299RHSA-2021:0397SUSE-SU-2021:0241-1SUSE-SU-2021:0245-1SUSE-SU-2021:0246-1SUSE-SU-2021:0257-1SUSE-SU-2021:0259-1SUSE-SU-2021:14609-1USN-4717-1
Timeline
- 26-02-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.
CVSS metrics
4 scores · 3 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 3 agree
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem 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
1.19%
Chance of exploitation in the next 30 days
Percentile
67%
Versus all other CVEs
30-day change
0.00 pp
From 1.19% on 19-09-2026
19-09-202619-10-2026
EPSS score1.19%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected 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
- firefox< 85 | < 85.0
- firefox_esr< 78.7
- thunderbird< 78.7
Debian2 products
- firefox-esr< 78.7.0esr-1
- thunderbird< 1:78.7.0-1
3 vendors · 11 products
References
11 links- bugzilla.mozilla.org/show_bug.cgi?id=1684020X Refsource MISCIssue TrackingPermissions RequiredVendor Advisory
