{"id":"CVE-2021-3639","details":"A flaw was found in mod_auth_mellon where it does not sanitize logout URLs properly. This issue could be used by an attacker to facilitate phishing attacks by tricking users into visiting a trusted web application URL that redirects to an external and potentially malicious server. The highest threat from this liability is to confidentiality and integrity.","modified":"2026-04-11T16:26:01.570748Z","published":"2022-08-22T15:15:13.633Z","related":["ALSA-2022:1934","SUSE-SU-2021:2912-1","SUSE-SU-2022:1524-1","openSUSE-SU-2024:13848-1"],"references":[{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1980648"},{"type":"FIX","url":"https://access.redhat.com/security/cve/CVE-2021-3639"},{"type":"FIX","url":"https://github.com/latchset/mod_auth_mellon/commit/42a11261b9dad2e48d70bdff7c53dd57a12db6f5"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/latchset/mod_auth_mellon","events":[{"introduced":"0"},{"fixed":"d5cfa396f69ba2ee0d1048fe59c2f0f4a6d077ef"},{"fixed":"42a11261b9dad2e48d70bdff7c53dd57a12db6f5"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"0.18.0"}]}}],"versions":["v0.10.0","v0.11.0","v0.12.0","v0.13.0","v0.13.1","v0.14.0","v0.14.1","v0.14.2","v0.15.0","v0.17.0","v0.4.0","v0.5.0","v0.6.0","v0.6.0-rc1","v0.6.1","v0.7.0","v0.8.0","v0.9.0","v0.9.1","v0_16_0"],"database_specific":{"vanir_signatures":[{"signature_version":"v1","source":"https://github.com/latchset/mod_auth_mellon/commit/42a11261b9dad2e48d70bdff7c53dd57a12db6f5","id":"CVE-2021-3639-06f962b5","digest":{"function_hash":"83105587025666378258602412050770007892","length":455},"deprecated":false,"signature_type":"Function","target":{"file":"auth_mellon_util.c","function":"am_check_url"}},{"signature_version":"v1","source":"https://github.com/latchset/mod_auth_mellon/commit/42a11261b9dad2e48d70bdff7c53dd57a12db6f5","id":"CVE-2021-3639-cc818928","digest":{"threshold":0.9,"line_hashes":["280196004057991006795901954659145925227","61501412547766912992816068119698943885","121989369976254605987379571555865310157","28373241189536936529294675472970530512","210226503878164329466142730749373246164","144331043775858122924234340824680977387"]},"deprecated":false,"signature_type":"Line","target":{"file":"auth_mellon_util.c"}}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-3639.json","vanir_signatures_modified":"2026-04-11T16:26:01Z"}}],"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"}]}