{"id":"UBUNTU-CVE-2021-44273","details":"e2guardian v5.4.x \u003c= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.","modified":"2026-05-20T16:06:30.137719978Z","published":"2021-12-23T12:15:00Z","upstream":["CVE-2021-44273"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-44273"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2021/12/23/2"},{"type":"REPORT","url":"https://github.com/e2guardian/e2guardian/issues/707"},{"type":"REPORT","url":"https://github.com/e2guardian/e2guardian/commit/eae46a7e2a57103aadca903c4a24cca94dc502a2"},{"type":"REPORT","url":"http://www.openwall.com/lists/oss-security/2021/12/23/2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-44273"}],"affected":[{"package":{"name":"e2guardian","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/e2guardian?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.0.3-2"],"ecosystem_specific":{"binaries":[{"binary_name":"e2guardian","binary_version":"3.4.0.3-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44273.json"}},{"package":{"name":"e2guardian","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/e2guardian?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.3.3-1","5.3.4-1"],"ecosystem_specific":{"binaries":[{"binary_name":"e2guardian","binary_version":"5.3.4-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44273.json"}},{"package":{"name":"e2guardian","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/e2guardian?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.3.4-2","5.3.5-1","5.3.5-2","5.3.5-2build1","5.3.5-3"],"ecosystem_specific":{"binaries":[{"binary_version":"5.3.5-3","binary_name":"e2guardian"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44273.json"}},{"package":{"name":"e2guardian","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/e2guardian?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.3.5-4.1ubuntu1","5.3.5-6ubuntu1","5.3.5-6ubuntu2","5.3.5-6ubuntu3"],"ecosystem_specific":{"binaries":[{"binary_name":"e2guardian","binary_version":"5.3.5-6ubuntu3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44273.json"}},{"package":{"name":"e2guardian","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/e2guardian?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.5.7-1","5.5.8-1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.5.8-1","binary_name":"e2guardian"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44273.json"}},{"package":{"name":"e2guardian","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/e2guardian?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.5.8-1","5.5.9-2"],"ecosystem_specific":{"binaries":[{"binary_name":"e2guardian","binary_version":"5.5.9-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44273.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}