UBUNTU-CVE-2021-23991

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    UBUNTU-CVE-2021-23991

    Published: 13 Apr 2021Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-23991

    Summary:

    Details: If a Thunderbird user has previously imported Alice's OpenPGP key, and Alice has extended the validity period of her key, but Alice's updated key has not yet been imported, an attacker may send an email containing a crafted version of Alice's key with an invalid subkey, Thunderbird might subsequently attempt to use the invalid subkey, and will fail to send encrypted email to Alice. This vulnerability affects Thunderbird < 78.9.1.

    References: https://ubuntu.com/security/CVE-2021-23991, https://www.mozilla.org/en-US/security/advisories/mfsa2021-13/#CVE-2021-23991, https://ubuntu.com/security/notices/USN-4995-1, https://ubuntu.com/security/notices/USN-4995-2, https://www.cve.org/CVERecord?id=CVE-2021-23991

    Affected packages

    Package

    Name: thunderbird

    Purl: pkg:deb/ubuntu/thunderbird@1:78.11.0+build1-0ubuntu0.18.04.2?arch=source&distro=bionic

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -1:78.11.0+build1-0ubuntu0.18.04.2

    Affected versions

    1:52.4.0+build1-0ubuntu2

    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-2021-23991 | CVE-DB