CVE-2021-29967

Mozilla developers reported memory safety bugs present in Firefox 88 and Firefox ESR 78.11. 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 Thunderbird < 78.11, Firefox < 89, and Firefox ESR < 78.11.

• CWE-787

• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1602862%2C1703191%2C1703760%2C1704722%2C1706041Issue Tracking, Not Applicable, Third Party Advisory
• https://security.gentoo.org/glsa/202208-14Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-23/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-24/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-26/Release Notes, Vendor Advisory
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1602862%2C1703191%2C1703760%2C1704722%2C1706041Issue Tracking, Not Applicable, Third Party Advisory
• https://security.gentoo.org/glsa/202208-14Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-23/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-24/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-26/Release Notes, Vendor Advisory

Published

Jun 24, 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.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-29961When styling and rendering an oversized `<select>` element, …4.3
• CVE-2021-29962Firefox for Android would become unstable and hard-to-recove…4.3
• CVE-2021-29963Address bar search suggestions in private browsing mode were…4.3
• CVE-2021-29964A locally-installed hostile program could send `WM_COPYDATA`…7.1
• CVE-2021-29965A malicious website that causes an HTTP Authentication dialo…5.3
• CVE-2021-29966Mozilla developers reported memory safety bugs present in Fi…8.8
• CVE-2021-29968When drawing text onto a canvas with WebRender disabled, an …8.1
• CVE-2021-29969If Thunderbird was configured to use STARTTLS for an IMAP co…5.9
• CVE-2021-29970A malicious webpage could have triggered a use-after-free, m…8.8
• CVE-2021-29971If a user had granted a permission to a webpage and saved th…9.8
• CVE-2021-29972A use-after-free vulnerability was found via testing, and tr…8.8
• CVE-2021-29973Password autofill was enabled without user interaction on in…8.8