CVE-2021-43855

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    CVE-2021-43855

    Published: 27 Dec 2021Last Modified: 9 Jul 2026

    Summary:

    Details: Wiki.js is a wiki app built on node.js. Wiki.js 2.5.263 and earlier is vulnerable to stored cross-site scripting through a SVG file upload made via a custom request with a fake MIME type. By creating a crafted SVG file, a malicious Wiki.js user may stage a stored cross-site scripting attack. This allows the attacker to execute malicious JavaScript when the SVG is viewed directly by other users. Scripts do not execute when loaded inside a page via normal `<img>` tags. The malicious SVG can only be uploaded by crafting a custom request to the server with a fake MIME type. A patch in version 2.5.264 fixes this vulnerability by adding an additional file extension verification check to the optional (enabled by default) SVG sanitization step to all file uploads that match the SVG mime type. As a workaround, disable file upload for all non-trusted users.

    References: https://github.com/Requarks/wiki/releases/tag/2.5.264, https://github.com/Requarks/wiki/commit/57b56d3a5b9c00358814e76f3ee5b4bb353ad62f, https://github.com/Requarks/wiki/security/advisories/GHSA-4893-pj5w-3hq9

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -43cc114ff04797906c80ecd7b81fda68fef3a883

    Affected versions

    2.5.260
    2.5.255
    2.5.254
    2.5.219
    2.5.214
    2.5.201
    2.5.197
    2.5.191
    2.5.170
    2.5.159
    2.5.144
    2.5.136
    2.5.132
    2.5.126
    2.5.121
    2.5.117
    2.5.105

    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-2021-43855 | CVE-DB