---
id: CVE-2020-25710
title: A flaw was found in OpenLDAP in versions before 2.4.56
summary: >-
  A flaw was found in OpenLDAP in versions before 2.4.56. This flaw allows an
  attacker who sends a malicious packet processed by OpenLDAP to force a failed
  assertion in csnNormalize23(). The highest threat from this vulnerability is
  to sys…
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-617
vendor: openldap
product: openldap
affected:
  - openldap < 2.4.56
  - jboss_core_services
  - jboss_enterprise_application_platform = 5.0.0
  - jboss_enterprise_web_server = 2.0.0
  - enterprise_linux = 5.0
  - enterprise_linux = 6.0
  - enterprise_linux = 7.0
  - debian_linux = 9.0
  - fedora = 33
patched:
  - openldap 2.4.56
published: '2021-05-28'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T10:17:33.353'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-25710'
references:
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1899678'
    label: secalert@redhat.com
  - url: >-
      https://git.openldap.org/openldap/openldap/-/commit/ab3915154e69920d480205b4bf5ccb2b391a0a1f#a2feb6ed0257c21c6672793ee2f94eaadc10c72c
    label: secalert@redhat.com
  - url: >-
      https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
    label: secalert@redhat.com
  - url: >-
      https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
    label: secalert@redhat.com
  - url: 'https://lists.debian.org/debian-lts-announce/2020/12/msg00008.html'
    label: secalert@redhat.com
  - url: 'https://security.netapp.com/advisory/ntap-20210716-0003/'
    label: secalert@redhat.com
  - url: 'https://www.debian.org/security/2020/dsa-4792'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1899678'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.openldap.org/openldap/openldap/-/commit/ab3915154e69920d480205b4bf5ccb2b391a0a1f#a2feb6ed0257c21c6672793ee2f94eaadc10c72c
    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/2020/12/msg00008.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20210716-0003/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2020/dsa-4792'
    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: 0.02666
epssPercentile: 0.85361
ingestedAt: '2026-10-14T10:25:41.190Z'
---

## Overview

A flaw was found in OpenLDAP in versions before 2.4.56. This flaw allows an attacker who sends a malicious packet processed by OpenLDAP to force a failed assertion in csnNormalize23(). The highest threat from this vulnerability is to system availability.

## Affected

- `openldap < 2.4.56`
- `jboss_core_services`
- `jboss_enterprise_application_platform = 5.0.0`
- `jboss_enterprise_web_server = 2.0.0`
- `enterprise_linux = 5.0`
- `enterprise_linux = 6.0`
- `enterprise_linux = 7.0`
- `debian_linux = 9.0`
- `fedora = 33`

## Remediation

Upgrade past the affected range:

- `openldap 2.4.56`