UBUNTU-CVE-2021-38506

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    UBUNTU-CVE-2021-38506

    Published: 3 Nov 2021Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-38506

    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://ubuntu.com/security/CVE-2021-38506, https://www.mozilla.org/en-US/security/advisories/mfsa2021-48/#CVE-2021-38506, https://www.mozilla.org/en-US/security/advisories/mfsa2021-49/#CVE-2021-38506, https://ubuntu.com/security/notices/USN-5131-1, https://ubuntu.com/security/notices/USN-5152-1, https://ubuntu.com/security/notices/USN-5248-1, https://www.cve.org/CVERecord?id=CVE-2021-38506

    Affected packages

    Package

    Name: firefox

    Purl: pkg:deb/ubuntu/[email protected]+build3-0ubuntu0.18.04.1?arch=source&distro=bionic

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -94.0+build3-0ubuntu0.18.04.1

    Affected versions

    56.0+build6-0ubuntu1

    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
    UBUNTU-CVE-2021-38506 | CVE-DB