CVE-2021-38506

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    CVE-2021-38506

    Published: 8 Dec 2021Last Modified: 16 Apr 2026

    Summary:

    Details: Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

    References: https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html, https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html, https://security.gentoo.org/glsa/202208-14, https://www.debian.org/security/2022/dsa-5034, https://www.mozilla.org/security/advisories/mfsa2021-48/, https://www.mozilla.org/security/advisories/mfsa2021-50/, https://security.gentoo.org/glsa/202202-03, https://www.debian.org/security/2021/dsa-5026, https://www.mozilla.org/security/advisories/mfsa2021-49/, https://bugzilla.mozilla.org/show_bug.cgi?id=1730750

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2021-38506 | CVE-DB