CVE-2021-43538: debian debian_linux Race Condition
CVSS: 4.3v3.1MediumModified
AliasesUBUNTU-CVE-2021-43538DEBIAN-CVE-2021-43538
Published 08-12-2021Last modified 04-08-2024
Vulnerability summary
CVE-2021-43538 is a medium (CVSS 4.3) Race Condition vulnerability in debian debian_linux. EPSS estimates a 1.24% chance of exploitation in the next 30 days, higher than 68.8% of scored vulnerabilities.
CVSS score
4.3/10
010
Medium · v3.1 (NVD)EPSS score
1.24%
0%100%
Low · +0.09 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 30 · Related 14DLA-2863-1DLA-2874-1DSA-5026-1DSA-5034-1MGASA-2021-0551MGASA-2021-0554OPENSUSE-SU-2021:1575-1OPENSUSE-SU-2021:1635-1OPENSUSE-SU-2021:3993-1OPENSUSE-SU-2021:4150-1OPENSUSE-SU-2024:11669-1OPENSUSE-SU-2024:11670-1OPENSUSE-SU-2024:14572-1RHSA-2021:5013RHSA-2021:5014RHSA-2021:5015RHSA-2021:5016RHSA-2021:5017RHSA-2021:5045RHSA-2021:5046RHSA-2021:5047RHSA-2021:5048RHSA-2021:5055SUSE-SU-2021:14859-1SUSE-SU-2021:3993-1SUSE-SU-2021:3995-1SUSE-SU-2021:4000-1SUSE-SU-2021:4150-1USN-5186-1USN-5248-1
Timeline
- 08-12-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.
CVSS metrics
4 scores · 3 sources · 2 versionsMedium 4.3Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:NSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
- OSV · DebianEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Medium 4.3Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:N/I:P/A:NSourcesSingle source
EPSS trend
Probability
1.24%
Chance of exploitation in the next 30 days
Percentile
69%
Versus all other CVEs
30-day change
+0.09 pp
From 1.16% on 19-09-2026
19-09-202619-10-2026
EPSS score1.24%
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< 95.0+build1-0ubuntu0.18.04.1 | < 95.0+build1-0ubuntu0.20.04.1 | < 95.0+build1-0ubuntu1
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
- mozjs78All versions (No fix recorded)
Debian3 products
- firefox-esr< 91.4.0esr-1
- thunderbird< 1:91.4.0-1
- debian_linuxEOL9.0 | 10.0 | 11.0
Mozilla3 products
- firefox≥ unspecified, < 95 | < 95.0
- firefox_esr≥ unspecified, < 91.4.0 | < 91.4.0
- thunderbird≥ unspecified, < 91.4.0 | < 91.4.0
3 vendors · 12 products
References
19 links- bugzilla.mozilla.org/show_bug.cgi?id=1739091X Refsource MISCIssue TrackingPermissions RequiredVendor Advisory
- lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing ListX Refsource MLISTThird Party Advisory
- lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListX Refsource MLISTThird Party Advisory