UBUNTU-CVE-2021-39191

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    UBUNTU-CVE-2021-39191

    Published: 3 Sept 2021Last Modified: 24 Oct 2025
    Upstream:
    CVE-2021-39191

    Summary:

    Details: mod_auth_openidc is an authentication/authorization module for the Apache 2.x HTTP server that functions as an OpenID Connect Relying Party, authenticating users against an OpenID Connect Provider. In versions prior to 2.4.9.4, the 3rd-party init SSO functionality of mod_auth_openidc was reported to be vulnerable to an open redirect attack by supplying a crafted URL in the `target_link_uri` parameter. A patch in version 2.4.9.4 made it so that the `OIDCRedirectURLsAllowed` setting must be applied to the `target_link_uri` parameter. There are no known workarounds aside from upgrading to a patched version.

    References: https://ubuntu.com/security/CVE-2021-39191, https://github.com/zmartzone/mod_auth_openidc/issues/672, https://github.com/zmartzone/mod_auth_openidc/commit/03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d, https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9.4, https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-2pgf-8h6h-gqg2, https://www.cve.org/CVERecord?id=CVE-2021-39191

    Affected packages

    Package

    Name: libapache2-mod-auth-openidc

    Purl: pkg:deb/ubuntu/[email protected]?arch=source&distro=bionic

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    2.1.6-1

    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-2021-39191 | CVE-DB