{"id":"USN-4738-1","summary":"openssl, openssl1.0 vulnerabilities","details":"Paul Kehrer discovered that OpenSSL incorrectly handled certain input\nlengths in EVP functions. A remote attacker could possibly use this issue\nto cause OpenSSL to crash, resulting in a denial of service.\n(CVE-2021-23840)\n\nTavis Ormandy discovered that OpenSSL incorrectly handled parsing issuer\nfields. A remote attacker could possibly use this issue to cause OpenSSL to\ncrash, resulting in a denial of service. (CVE-2021-23841)\n","modified":"2026-02-10T04:42:03Z","published":"2021-02-18T12:22:41Z","related":["UBUNTU-CVE-2021-23840","UBUNTU-CVE-2021-23841"],"upstream":["CVE-2021-23840","CVE-2021-23841","UBUNTU-CVE-2021-23840","UBUNTU-CVE-2021-23841"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4738-1"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-23840"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-23841"}],"affected":[{"package":{"name":"openssl","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/openssl@1.0.2g-1ubuntu4.19?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.2g-1ubuntu4.19"}]}],"versions":["1.0.2d-0ubuntu1","1.0.2d-0ubuntu2","1.0.2e-1ubuntu1","1.0.2f-2ubuntu1","1.0.2g-1ubuntu2","1.0.2g-1ubuntu3","1.0.2g-1ubuntu4","1.0.2g-1ubuntu4.1","1.0.2g-1ubuntu4.2","1.0.2g-1ubuntu4.4","1.0.2g-1ubuntu4.5","1.0.2g-1ubuntu4.6","1.0.2g-1ubuntu4.8","1.0.2g-1ubuntu4.9","1.0.2g-1ubuntu4.10","1.0.2g-1ubuntu4.11","1.0.2g-1ubuntu4.12","1.0.2g-1ubuntu4.13","1.0.2g-1ubuntu4.14","1.0.2g-1ubuntu4.15","1.0.2g-1ubuntu4.16","1.0.2g-1ubuntu4.17","1.0.2g-1ubuntu4.18"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"1.0.2g-1ubuntu4.19","binary_name":"libssl-dev"},{"binary_version":"1.0.2g-1ubuntu4.19","binary_name":"libssl1.0.0"},{"binary_version":"1.0.2g-1ubuntu4.19","binary_name":"openssl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4738-1.json","cves_map":{"cves":[{"severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"low","type":"Ubuntu"}],"id":"CVE-2021-23840"},{"severity":[{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}],"id":"CVE-2021-23841"}],"ecosystem":"Ubuntu:16.04:LTS"}}},{"package":{"name":"openssl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/openssl@1.1.1-1ubuntu2.1~18.04.8?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.1-1ubuntu2.1~18.04.8"}]}],"versions":["1.0.2g-1ubuntu13","1.0.2g-1ubuntu14","1.0.2n-1ubuntu1","1.1.0g-2ubuntu1","1.1.0g-2ubuntu2","1.1.0g-2ubuntu3","1.1.0g-2ubuntu4","1.1.0g-2ubuntu4.1","1.1.0g-2ubuntu4.3","1.1.1-1ubuntu2.1~18.04.1","1.1.1-1ubuntu2.1~18.04.2","1.1.1-1ubuntu2.1~18.04.3","1.1.1-1ubuntu2.1~18.04.4","1.1.1-1ubuntu2.1~18.04.5","1.1.1-1ubuntu2.1~18.04.6","1.1.1-1ubuntu2.1~18.04.7"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"1.1.1-1ubuntu2.1~18.04.8","binary_name":"libssl-dev"},{"binary_version":"1.1.1-1ubuntu2.1~18.04.8","binary_name":"libssl1.1"},{"binary_version":"1.1.1-1ubuntu2.1~18.04.8","binary_name":"openssl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4738-1.json","cves_map":{"cves":[{"severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"low","type":"Ubuntu"}],"id":"CVE-2021-23840"},{"severity":[{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}],"id":"CVE-2021-23841"}],"ecosystem":"Ubuntu:18.04:LTS"}}},{"package":{"name":"openssl1.0","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/openssl1.0@1.0.2n-1ubuntu5.6?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.2n-1ubuntu5.6"}]}],"versions":["1.0.2n-1ubuntu2","1.0.2n-1ubuntu3","1.0.2n-1ubuntu4","1.0.2n-1ubuntu5","1.0.2n-1ubuntu5.1","1.0.2n-1ubuntu5.2","1.0.2n-1ubuntu5.3","1.0.2n-1ubuntu5.4","1.0.2n-1ubuntu5.5"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"1.0.2n-1ubuntu5.6","binary_name":"libssl1.0-dev"},{"binary_version":"1.0.2n-1ubuntu5.6","binary_name":"libssl1.0.0"},{"binary_version":"1.0.2n-1ubuntu5.6","binary_name":"openssl1.0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4738-1.json","cves_map":{"cves":[{"severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"low","type":"Ubuntu"}],"id":"CVE-2021-23840"},{"severity":[{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}],"id":"CVE-2021-23841"}],"ecosystem":"Ubuntu:18.04:LTS"}}},{"package":{"name":"openssl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/openssl@1.1.1f-1ubuntu2.2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.1f-1ubuntu2.2"}]}],"versions":["1.1.1c-1ubuntu4","1.1.1d-2ubuntu3","1.1.1d-2ubuntu6","1.1.1f-1ubuntu1","1.1.1f-1ubuntu2","1.1.1f-1ubuntu2.1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"1.1.1f-1ubuntu2.2","binary_name":"libssl-dev"},{"binary_version":"1.1.1f-1ubuntu2.2","binary_name":"libssl1.1"},{"binary_version":"1.1.1f-1ubuntu2.2","binary_name":"openssl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4738-1.json","cves_map":{"cves":[{"severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"low","type":"Ubuntu"}],"id":"CVE-2021-23840"},{"severity":[{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}],"id":"CVE-2021-23841"}],"ecosystem":"Ubuntu:20.04:LTS"}}}],"schema_version":"1.7.3"}