{"id":"CVE-2020-36227","title":"A flaw was discovered in OpenLDAP before 2.4.57 leading to an infinite loop in slapd with the cancel_extop Cancel operation, resulting in denial of service.","summary":"A flaw was discovered in OpenLDAP before 2.4.57 leading to an infinite loop in slapd with the cancel_extop Cancel operation, resulting in denial of service.","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-835"],"vendor":"openldap","product":"openldap","affected":["openldap < 2.4.57","debian_linux = 9.0","debian_linux = 10.0","macos >= 11.1, < 11.4"],"patched":["openldap 2.4.57","macos 11.4"],"published":"2021-01-26","updated":"2026-10-14","sourceUpdated":"2026-10-14T10:17:37.133","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2020-36227","references":[{"url":"http://seclists.org/fulldisclosure/2021/May/64","label":"cve@mitre.org"},{"url":"http://seclists.org/fulldisclosure/2021/May/65","label":"cve@mitre.org"},{"url":"http://seclists.org/fulldisclosure/2021/May/70","label":"cve@mitre.org"},{"url":"https://bugs.openldap.org/show_bug.cgi?id=9428","label":"cve@mitre.org"},{"url":"https://git.openldap.org/openldap/openldap/-/commit/9d0e8485f3113505743baabf1167e01e4558ccf5","label":"cve@mitre.org"},{"url":"https://git.openldap.org/openldap/openldap/-/tags/OPENLDAP_REL_ENG_2_4_57","label":"cve@mitre.org"},{"url":"https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E","label":"cve@mitre.org"},{"url":"https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E","label":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2021/02/msg00005.html","label":"cve@mitre.org"},{"url":"https://security.netapp.com/advisory/ntap-20210226-0002/","label":"cve@mitre.org"},{"url":"https://support.apple.com/kb/HT212529","label":"cve@mitre.org"},{"url":"https://support.apple.com/kb/HT212530","label":"cve@mitre.org"},{"url":"https://support.apple.com/kb/HT212531","label":"cve@mitre.org"},{"url":"https://www.debian.org/security/2021/dsa-4845","label":"cve@mitre.org"},{"url":"http://seclists.org/fulldisclosure/2021/May/64","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://seclists.org/fulldisclosure/2021/May/65","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://seclists.org/fulldisclosure/2021/May/70","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugs.openldap.org/show_bug.cgi?id=9428","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.openldap.org/openldap/openldap/-/commit/9d0e8485f3113505743baabf1167e01e4558ccf5","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.openldap.org/openldap/openldap/-/tags/OPENLDAP_REL_ENG_2_4_57","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2021/02/msg00005.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20210226-0002/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/kb/HT212529","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/kb/HT212530","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/kb/HT212531","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2021/dsa-4845","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd"],"epss":0.77236,"epssPercentile":0.99548,"ingestedAt":"2026-10-14T10:25:41.186Z","slug":"CVE-2020-36227","body":"## Overview\n\nA flaw was discovered in OpenLDAP before 2.4.57 leading to an infinite loop in slapd with the cancel_extop Cancel operation, resulting in denial of service.\n\n## Affected\n\n- `openldap < 2.4.57`\n- `debian_linux = 9.0`\n- `debian_linux = 10.0`\n- `macos >= 11.1, < 11.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `openldap 2.4.57`\n- `macos 11.4`","depth":"twilight","depthScore":57,"depthScoreParts":{"impact":41.3,"likelihood":15.4,"exploitation":0,"ransomware":0},"changes":[]}