{"id":"UBUNTU-CVE-2021-22946","details":"A user can tell curl \u003e= 7.20.0 and \u003c= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server (`--ssl-reqd` on the command line or`CURLOPT_USE_SSL` set to `CURLUSESSL_CONTROL` or `CURLUSESSL_ALL` withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations **withoutTLS** contrary to the instructions and expectations, exposing possibly sensitive data in clear text over the network.","modified":"2026-04-27T09:09:05.058223Z","published":"2021-09-15T00:00:00Z","related":["USN-5079-1","USN-5079-2"],"upstream":["CVE-2021-22946"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-22946"},{"type":"REPORT","url":"https://curl.se/docs/CVE-2021-22946.html"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5079-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5079-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-22946"}],"affected":[{"package":{"name":"curl","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/curl@7.35.0-1ubuntu2.20+esm8?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.35.0-1ubuntu2.20+esm8"}]}],"versions":["7.32.0-1ubuntu1","7.33.0-1ubuntu1","7.34.0-1ubuntu1","7.35.0-1ubuntu1","7.35.0-1ubuntu2","7.35.0-1ubuntu2.1","7.35.0-1ubuntu2.2","7.35.0-1ubuntu2.3","7.35.0-1ubuntu2.5","7.35.0-1ubuntu2.6","7.35.0-1ubuntu2.7","7.35.0-1ubuntu2.8","7.35.0-1ubuntu2.9","7.35.0-1ubuntu2.10","7.35.0-1ubuntu2.11","7.35.0-1ubuntu2.12","7.35.0-1ubuntu2.13","7.35.0-1ubuntu2.14","7.35.0-1ubuntu2.15","7.35.0-1ubuntu2.16","7.35.0-1ubuntu2.17","7.35.0-1ubuntu2.19","7.35.0-1ubuntu2.20","7.35.0-1ubuntu2.20+esm2","7.35.0-1ubuntu2.20+esm3","7.35.0-1ubuntu2.20+esm4","7.35.0-1ubuntu2.20+esm5","7.35.0-1ubuntu2.20+esm6","7.35.0-1ubuntu2.20+esm7"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"curl","binary_version":"7.35.0-1ubuntu2.20+esm8"},{"binary_name":"libcurl3","binary_version":"7.35.0-1ubuntu2.20+esm8"},{"binary_name":"libcurl3-gnutls","binary_version":"7.35.0-1ubuntu2.20+esm8"},{"binary_name":"libcurl3-nss","binary_version":"7.35.0-1ubuntu2.20+esm8"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-22946.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/curl@7.47.0-1ubuntu2.19+esm1?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.47.0-1ubuntu2.19+esm1"}]}],"versions":["7.43.0-1ubuntu2","7.45.0-1ubuntu1","7.46.0-1ubuntu1","7.47.0-1ubuntu1","7.47.0-1ubuntu2","7.47.0-1ubuntu2.1","7.47.0-1ubuntu2.2","7.47.0-1ubuntu2.3","7.47.0-1ubuntu2.4","7.47.0-1ubuntu2.5","7.47.0-1ubuntu2.6","7.47.0-1ubuntu2.7","7.47.0-1ubuntu2.8","7.47.0-1ubuntu2.9","7.47.0-1ubuntu2.11","7.47.0-1ubuntu2.12","7.47.0-1ubuntu2.13","7.47.0-1ubuntu2.14","7.47.0-1ubuntu2.15","7.47.0-1ubuntu2.16","7.47.0-1ubuntu2.18","7.47.0-1ubuntu2.19"],"ecosystem_specific":{"binaries":[{"binary_name":"curl","binary_version":"7.47.0-1ubuntu2.19+esm1"},{"binary_name":"libcurl3","binary_version":"7.47.0-1ubuntu2.19+esm1"},{"binary_name":"libcurl3-gnutls","binary_version":"7.47.0-1ubuntu2.19+esm1"},{"binary_name":"libcurl3-nss","binary_version":"7.47.0-1ubuntu2.19+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-22946.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/curl@7.58.0-2ubuntu3.15?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.58.0-2ubuntu3.15"}]}],"versions":["7.55.1-1ubuntu2","7.55.1-1ubuntu2.1","7.57.0-1ubuntu1","7.58.0-2ubuntu1","7.58.0-2ubuntu2","7.58.0-2ubuntu3","7.58.0-2ubuntu3.1","7.58.0-2ubuntu3.2","7.58.0-2ubuntu3.3","7.58.0-2ubuntu3.5","7.58.0-2ubuntu3.6","7.58.0-2ubuntu3.7","7.58.0-2ubuntu3.8","7.58.0-2ubuntu3.9","7.58.0-2ubuntu3.10","7.58.0-2ubuntu3.12","7.58.0-2ubuntu3.13","7.58.0-2ubuntu3.14"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"curl","binary_version":"7.58.0-2ubuntu3.15"},{"binary_name":"libcurl3-gnutls","binary_version":"7.58.0-2ubuntu3.15"},{"binary_name":"libcurl3-nss","binary_version":"7.58.0-2ubuntu3.15"},{"binary_name":"libcurl4","binary_version":"7.58.0-2ubuntu3.15"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-22946.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/curl@7.68.0-1ubuntu2.7?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.68.0-1ubuntu2.7"}]}],"versions":["7.65.3-1ubuntu3","7.65.3-1ubuntu4","7.66.0-1ubuntu1","7.67.0-2ubuntu1","7.68.0-1ubuntu1","7.68.0-1ubuntu2","7.68.0-1ubuntu2.1","7.68.0-1ubuntu2.2","7.68.0-1ubuntu2.4","7.68.0-1ubuntu2.5","7.68.0-1ubuntu2.6"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"curl","binary_version":"7.68.0-1ubuntu2.7"},{"binary_name":"libcurl3-gnutls","binary_version":"7.68.0-1ubuntu2.7"},{"binary_name":"libcurl3-nss","binary_version":"7.68.0-1ubuntu2.7"},{"binary_version":"7.68.0-1ubuntu2.7","binary_name":"libcurl4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-22946.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/curl@7.74.0-1.3ubuntu2?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.74.0-1.3ubuntu2"}]}],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"curl","binary_version":"7.74.0-1.3ubuntu2"},{"binary_version":"7.74.0-1.3ubuntu2","binary_name":"libcurl3-gnutls"},{"binary_name":"libcurl3-nss","binary_version":"7.74.0-1.3ubuntu2"},{"binary_name":"libcurl4","binary_version":"7.74.0-1.3ubuntu2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-22946.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}