UBUNTU-CVE-2021-23953

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    UBUNTU-CVE-2021-23953

    Published: 26 Jan 2021Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-23953

    Summary:

    Details: If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

    References: https://ubuntu.com/security/CVE-2021-23953, https://www.mozilla.org/en-US/security/advisories/mfsa2021-04/#CVE-2021-23953, https://www.mozilla.org/en-US/security/advisories/mfsa2021-03/#CVE-2021-23953, https://ubuntu.com/security/notices/USN-4717-1, https://ubuntu.com/security/notices/USN-4736-1, https://www.cve.org/CVERecord?id=CVE-2021-23953

    Affected packages

    Package

    Name: firefox

    Purl: pkg:deb/ubuntu/[email protected]+build1-0ubuntu0.16.04.1?arch=source&distro=xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -85.0+build1-0ubuntu0.16.04.1

    Affected versions

    41.0.2+build2-0ubuntu1

    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-2021-23953 | CVE-DB