CVE-2021-43538

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.

• CWE-362

• https://bugzilla.mozilla.org/show_bug.cgi?id=1739091Issue Tracking, Permissions Required, Vendor Advisory
• https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing List, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202202-03Third Party Advisory
• https://security.gentoo.org/glsa/202208-14Third Party Advisory
• https://www.debian.org/security/2021/dsa-5026Third Party Advisory
• https://www.debian.org/security/2022/dsa-5034Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-52/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-53/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-54/Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1739091Issue Tracking, Permissions Required, Vendor Advisory
• https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing List, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202202-03Third Party Advisory
• https://security.gentoo.org/glsa/202208-14Third Party Advisory
• https://www.debian.org/security/2021/dsa-5026Third Party Advisory
• https://www.debian.org/security/2022/dsa-5034Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-52/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-53/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-54/Vendor Advisory

Published

Dec 8, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
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• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-43532The 'Copy Image Link' context menu action would copy the fin…6.1
• CVE-2021-43533When parsing internationalized domain names, high bits of th…4.3
• CVE-2021-43534Mozilla developers and community members reported memory saf…8.8
• CVE-2021-43535A use-after-free could have occured when an HTTP2 session ob…8.8
• CVE-2021-43536Under certain circumstances, asynchronous functions could ha…6.5
• CVE-2021-43537An incorrect type conversion of sizes from 64bit to 32bit in…8.8
• CVE-2021-43539Failure to correctly record the location of live pointers ac…8.8
• CVE-2021-4354The PWA for WP & AMP for WordPress is vulnerable to arbitrar…8.8
• CVE-2021-43540WebExtensions with the correct permissions were able to crea…6.5
• CVE-2021-43541When invoking protocol handlers for external protocols, a su…6.5
• CVE-2021-43542Using XMLHttpRequest, an attacker could have identified inst…6.5
• CVE-2021-43543Documents loaded with the CSP sandbox directive could have e…6.1