{"id":"CVE-2021-39191","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.","aliases":["GHSA-2pgf-8h6h-gqg2"],"modified":"2026-05-19T00:39:21.386270Z","published":"2021-09-03T14:15:07.210Z","related":["ALSA-2022:1823","SUSE-SU-2021:3352-1","SUSE-SU-2023:0215-1","SUSE-SU-2025:4532-1"],"database_specific":{"unresolved_ranges":[{"vendor_product":"debian:debian_linux","extracted_events":[{"last_affected":"10.0"}],"cpes":["cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*"],"source":"CPE_FIELD"},{"vendor_product":"fedoraproject:fedora","extracted_events":[{"last_affected":"35"},{"last_affected":"36"}],"cpes":["cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*","cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*"],"source":"CPE_FIELD"}]},"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/32RGPW5LZDLDTB7MKZIGAHPSLFOUNWR5/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RHXO4O4G2UQS7X6OQJCVZKHZAQ7SAIFB/"},{"type":"ADVISORY","url":"https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9.4"},{"type":"ADVISORY","url":"https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-2pgf-8h6h-gqg2"},{"type":"FIX","url":"https://github.com/zmartzone/mod_auth_openidc/commit/03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d"},{"type":"ARTICLE","url":"https://lists.debian.org/debian-lts-announce/2023/07/msg00020.html"},{"type":"EVIDENCE","url":"https://github.com/zmartzone/mod_auth_openidc/issues/672"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openidc/mod_auth_openidc","events":[{"introduced":"0"},{"fixed":"03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"2.4.9.4"}],"cpe":"cpe:2.3:a:openidc:mod_auth_openidc:*:*:*:*:*:*:*:*","source":["CPE_FIELD","REFERENCES"]}}],"versions":["v2.4.9.3","v2.4.9.2","v2.4.9.1","v2.4.9","v2.4.8.4","v2.4.8.3","v2.4.8.2","v2.4.8.1","v2.4.7.2","v2.4.7.1","v2.4.7","v2.4.6","v2.4.5","v2.4.4.1","v2.4.4","v2.4.3","v2.4.2.1","v2.4.2","v2.4.1","v2.4.0.4","v2.4.0.3","v2.4.0.2","v2.4.0.1","v2.4.0","v2.3.11","2.3.11rc1","v2.3.10.2","v2.3.10.1","v2.3.10","v2.3.9","v2.3.8","v2.3.7","v2.3.6","v2.3.5","v2.3.4","v2.3.3","v2.3.2","v2.3.1","v2.3.0","v2.3.0rc3","v2.3.0rc0","v2.2.0","v2.1.6","v2.1.5","v2.1.4","v2.1.3","v2.1.2","v2.1.1","v2.1.0","v2.0.0","v2.0.0rc4","v2.0.0rc1","v1.8.10","v1.8.9","v1.8.8","v1.8.7","v1.8.6","v1.8.5","v1.8.4","v1.8.3","v1.8.2","v1.8.1","v1.8.0","v1.7.0","v1.6.0","v1.5.5","v1.5.4","v1.5.3","v1.5.2","v1.5.1","v1.5"],"database_specific":{"vanir_signatures_modified":"2026-05-19T00:39:21Z","vanir_signatures":[{"target":{"file":"src/mod_auth_openidc.c","function":"oidc_handle_discovery_response"},"source":"https://github.com/openidc/mod_auth_openidc/commit/03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d","signature_version":"v1","signature_type":"Function","id":"CVE-2021-39191-1d53a487","deprecated":false,"digest":{"function_hash":"255789951588007788344141961223198622431","length":3326}}],"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-39191.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}