---
id: CVE-2020-36223
title: >-
  A flaw was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in
  the Values Return Filter control handling, resulting in denial of service
  (double free and out-of-bounds read).
summary: >-
  A flaw was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in
  the Values Return Filter control handling, resulting in denial of service
  (double free and out-of-bounds read).
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-125
  - CWE-415
vendor: openldap
product: openldap
affected:
  - openldap < 2.4.57
  - debian_linux = 9.0
  - debian_linux = 10.0
  - 'mac_os_x >= 10.14.0, < 10.14.6'
  - mac_os_x = 10.14.6
  - 'macos >= 11.1, < 11.4'
patched:
  - openldap 2.4.57
  - mac_os_x 10.14.6
  - macos 11.4
published: '2021-01-26'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T10:17:36.170'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-36223'
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=9408'
    label: cve@mitre.org
  - url: >-
      https://git.openldap.org/openldap/openldap/-/commit/21981053a1195ae1555e23df4d9ac68d34ede9dd
    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=9408'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.openldap.org/openldap/openldap/-/commit/21981053a1195ae1555e23df4d9ac68d34ede9dd
    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: 0.04184
epssPercentile: 0.90711
ingestedAt: '2026-10-14T10:25:41.185Z'
---

## Overview

A flaw was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Values Return Filter control handling, resulting in denial of service (double free and out-of-bounds read).

## Affected

- `openldap < 2.4.57`
- `debian_linux = 9.0`
- `debian_linux = 10.0`
- `mac_os_x >= 10.14.0, < 10.14.6`
- `mac_os_x = 10.14.6`
- `macos >= 11.1, < 11.4`

## Remediation

Upgrade past the affected range:

- `openldap 2.4.57`
- `mac_os_x 10.14.6`
- `macos 11.4`