UBUNTU-CVE-2021-33829

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    UBUNTU-CVE-2021-33829

    Published: 9 Jun 2021Last Modified: 4 Feb 2026
    Upstream:
    CVE-2021-33829

    Summary:

    Details: A cross-site scripting (XSS) vulnerability in the HTML Data Processor in CKEditor 4 4.14.0 through 4.16.x before 4.16.1 allows remote attackers to inject executable JavaScript code through a crafted comment because --!> is mishandled.

    References: https://ubuntu.com/security/CVE-2021-33829, https://ckeditor.com/blog/ckeditor-4.16.1-with-accessibility-enhancements/#improvements-for-comments-in-html-parser, https://github.com/ckeditor/ckeditor4/commit/3e426ce34f7fc7bf784624358831ef9e189bb6ed, https://ubuntu.com/security/notices/USN-5340-1, https://www.cve.org/CVERecord?id=CVE-2021-33829, https://ubuntu.com/security/notices/USN-5340-2

    Affected packages

    Package

    Name: ckeditor

    Purl: pkg:deb/ubuntu/[email protected]+dfsg-2ubuntu0.16.04.1~esm1?arch=source&distro=esm-apps/xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -4.5.7+dfsg-2ubuntu0.16.04.1~esm1

    Affected versions

    4.4.4+dfsg1-3

    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-2021-33829 | CVE-DB