{"id":"UBUNTU-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":"2026-02-04T03:40:54.478355Z","published":"2021-08-04T00:00:00Z","related":["USN-5069-1","USN-5069-2"],"upstream":["CVE-2021-3639"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-3639"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5069-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5069-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-3639"}],"affected":[{"package":{"name":"libapache2-mod-auth-mellon","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libapache2-mod-auth-mellon@0.12.0-2+deb9u1build0.16.04.1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.10.0-1","0.11.0-1","0.12.0-1","0.12.0-2+deb9u1build0.16.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libapache2-mod-auth-mellon","binary_version":"0.12.0-2+deb9u1build0.16.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3639.json"}},{"package":{"name":"libapache2-mod-auth-mellon","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libapache2-mod-auth-mellon@0.13.1-1ubuntu0.3?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.13.1-1ubuntu0.3"}]}],"versions":["0.13.1-1","0.13.1-1build1","0.13.1-1build2","0.13.1-1ubuntu0.1","0.13.1-1ubuntu0.2"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libapache2-mod-auth-mellon","binary_version":"0.13.1-1ubuntu0.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3639.json"}},{"package":{"name":"libapache2-mod-auth-mellon","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libapache2-mod-auth-mellon@0.16.0-1ubuntu0.1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.16.0-1ubuntu0.1"}]}],"versions":["0.14.2-1ubuntu1","0.14.2-1ubuntu2","0.16.0-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libapache2-mod-auth-mellon","binary_version":"0.16.0-1ubuntu0.1"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3639.json"}},{"package":{"name":"libapache2-mod-auth-mellon","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libapache2-mod-auth-mellon@0.17.0-1ubuntu1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.17.0-1ubuntu1"}]}],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libapache2-mod-auth-mellon","binary_version":"0.17.0-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3639.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}