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    CVE-2021-39191

    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.

    Published:Sep 3, 2021
    Last Modified:Nov 21, 2024
    EPS:Sep 3, 2021
    EPSS Score:0.00371
    CVSS Score:4.7

    Affected Products

    Vendor
    Debian
    Product
    Debian Linux
    Vendor
    Fedoraproject
    Product
    Fedora
    Vendor
    Openidc
    Product
    Mod Auth Openidc
    Vendor
    Redhat
    Product
    Enterprise Linux

    Exploits

    https://github.com/zmartzone/mod_auth_openidc/issues/672https://github.com/zmartzone/mod_auth_openidc/issues/672

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-178 Cross-Site Flashing

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    References

    https://github.com/zmartzone/mod_auth_openidc/commit/03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d
    https://github.com/zmartzone/mod_auth_openidc/issues/672
    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://lists.debian.org/debian-lts-announce/2023/07/msg00020.html
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/32RGPW5LZDLDTB7MKZIGAHPSLFOUNWR5/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RHXO4O4G2UQS7X6OQJCVZKHZAQ7SAIFB/
    https://github.com/zmartzone/mod_auth_openidc/commit/03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d
    https://github.com/zmartzone/mod_auth_openidc/issues/672
    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://lists.debian.org/debian-lts-announce/2023/07/msg00020.html
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/32RGPW5LZDLDTB7MKZIGAHPSLFOUNWR5/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RHXO4O4G2UQS7X6OQJCVZKHZAQ7SAIFB/

    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