{"id":"CVE-2021-22945","title":"When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.","summary":"When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cwe":["CWE-415","CWE-415","CWE-415"],"vendor":"haxx","product":"libcurl","affected":["libcurl >= 7.73.0, <= 7.78.0","fedora = 33","fedora = 35","cloud_backup","clustered_data_ontap","mysql_server >= 5.7.0, <= 5.7.35","mysql_server >= 8.0.0, <= 8.0.26","h300s_firmware","h500s_firmware","h700s_firmware","h300e_firmware","h500e_firmware","h700e_firmware","h410s_firmware","solidfire_baseboard_management_controller_firmware","macos >= 12.0.0, < 12.3","sinec_ins < 1.0.1.1","debian_linux = 11.0","universal_forwarder >= 8.2.0, < 8.2.12","universal_forwarder >= 9.0.0, < 9.0.6","universal_forwarder = 9.1.0"],"patched":["macos 12.3","sinec_ins 1.0.1.1","universal_forwarder 9.0.6"],"published":"2021-09-23","updated":"2026-10-14","sourceUpdated":"2026-10-14T12:17:08.693","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-22945","references":[{"url":"http://seclists.org/fulldisclosure/2022/Mar/29","label":"support@hackerone.com"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf","label":"support@hackerone.com"},{"url":"https://hackerone.com/reports/1269242","label":"support@hackerone.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/","label":"support@hackerone.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/","label":"support@hackerone.com"},{"url":"https://security.gentoo.org/glsa/202212-01","label":"support@hackerone.com"},{"url":"https://security.netapp.com/advisory/ntap-20211029-0003/","label":"support@hackerone.com"},{"url":"https://support.apple.com/kb/HT213183","label":"support@hackerone.com"},{"url":"https://www.debian.org/security/2022/dsa-5197","label":"support@hackerone.com"},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","label":"support@hackerone.com"},{"url":"http://seclists.org/fulldisclosure/2022/Mar/29","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hackerone.com/reports/1269242","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202212-01","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20211029-0003/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/kb/HT213183","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2022/dsa-5197","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-389290.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd"],"epss":0.06677,"epssPercentile":0.93762,"ingestedAt":"2026-10-14T12:29:10.826Z","slug":"CVE-2021-22945","body":"## Overview\n\nWhen sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.\n\n## Affected\n\n- `libcurl >= 7.73.0, <= 7.78.0`\n- `fedora = 33`\n- `fedora = 35`\n- `cloud_backup`\n- `clustered_data_ontap`\n- `mysql_server >= 5.7.0, <= 5.7.35`\n- `mysql_server >= 8.0.0, <= 8.0.26`\n- `h300s_firmware`\n- `h500s_firmware`\n- `h700s_firmware`\n- `h300e_firmware`\n- `h500e_firmware`\n- `h700e_firmware`\n- `h410s_firmware`\n- `solidfire_baseboard_management_controller_firmware`\n- `macos >= 12.0.0, < 12.3`\n- `sinec_ins < 1.0.1.1`\n- `debian_linux = 11.0`\n- `universal_forwarder >= 8.2.0, < 8.2.12`\n- `universal_forwarder >= 9.0.0, < 9.0.6`\n- `universal_forwarder = 9.1.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `macos 12.3`\n- `sinec_ins 1.0.1.1`\n- `universal_forwarder 9.0.6`","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":50.1,"likelihood":1.3,"exploitation":0,"ransomware":0},"changes":[]}