CVE-2023-2953Network attack vector

Service interruption via unchecked URL allocation failures

Published May 30, 2023 · Updated Jan 10, 2025

NULL-pointer dereference in OpenLDAP 2.4 allows remote attackers to crash an OpenLDAP process after a URL-string allocation fails. The ldif_open_url path passes an unchecked ber_strdup result onward, while ldap_url_parsehosts dereferences an unchecked duplicated scheme. Triggering the crash requires allocation failure, so the bounded impact is a process-level service interruption.

CVSS severity7.5
High
EPSS probability1.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL-pointer dereference in OpenLDAP 2.4 allows remote attackers to crash an OpenLDAP process after a URL-string allocation fails. The ldif_open_url path passes an unchecked ber_strdup result onward, while ldap_url_parsehosts dereferences an unchecked duplicated scheme. Triggering the crash requires allocation failure, so the bounded impact is a process-level service interruption.

The record

CVE
CVE-2023-2953
Published
May 30, 2023
Updated
Jan 10, 2025
Vendor
OpenLDAP Foundation
Product
OpenLDAP Software
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 30, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=openldap-2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenLDAP Foundation · OpenLDAP Softwareversion=openldap-2.4

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.1Oracle LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
5.9Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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