CVE-2021-29987

After requesting multiple permissions, and closing the first permission panel, subsequent permission panels will be displayed in a different position but still record a click in the default location, making it possible to trick a user into accepting a permission they did not want to. *This bug only affects Firefox on Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox < 91 and Thunderbird < 91.

• CWE-307

• https://bugzilla.mozilla.org/show_bug.cgi?id=1716129Issue Tracking, Vendor Advisory
• https://security.gentoo.org/glsa/202202-03Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-33/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-36/Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1716129Issue Tracking, Vendor Advisory
• https://security.gentoo.org/glsa/202202-03Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-33/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-36/Vendor Advisory

Published

Aug 17, 2021

Last Modified

Jun 17, 2026

Status

Modified

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• CVE-2021-29984Instruction reordering resulted in a sequence of instruction…8.8
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• CVE-2021-29988Firefox incorrectly treated an inline list-item element as a…8.8
• CVE-2021-29989Mozilla developers reported memory safety bugs present in Fi…8.8
• CVE-2021-29990Mozilla developers and community members reported memory saf…8.8
• CVE-2021-29991Firefox incorrectly accepted a newline in a HTTP/3 header, i…8.1
• CVE-2021-29993Firefox for Android allowed navigations through the `intent:…8.1
• CVE-2021-29994Cloudera Hue 4.6.0 allows XSS.6.1