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Enterprise LinuxOperating system · Redhat

CVE-2023-2953

HIGH · 7.5 CVSS v3.1 Published 2023-05-30
Fix available
A fix is available. Upgrade to 11.7.9 / 12.6.8 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability was found in openldap. This security flaw causes a null pointer dereference in ber_memalloc_x() function.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A null pointer dereference vulnerability exists in OpenLDAP's ber_memalloc_x() function, which handles memory allocation for BER encoding. When the memory allocation fails or returns NULL, the code attempts to dereference the null pointer, causing a crash. This could lead to denial of service in LDAP operations.

MitigationApply the vendor-supplied patch or update to a patched version of OpenLDAP that fixes the ber_memalloc_x() null pointer handling. Test in a staging environment before production deployment.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Enterprise LinuxOperating system
Affected:= 8.0= 9.0
OpenldapApplication
Affected:= 2.4
macOSOperating system
Affected:>= 11.0, < 11.7.9>= 12.0, < 12.6.8>= 13.0, < 13.5
Active Iq Unified ManagerApplication
Affected:all versions
Clustered Data OntapApplication
Affected:all versions
Ontap ToolsApplication
Affected:all versions
H300s FirmwareOperating system
Affected:all versions
H500s FirmwareOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check OpenLDAP version on Linux systems
    Run `ldapsearch -V` or `slapd -V` to identify the installed OpenLDAP version
    Affected if Version is 2.4.x (any patch level) or if running on RHEL 8.0 or 9.0 with OpenLDAP installed
  2. Verify if LDAP services are active
    Check if slapd or ldap services are running using `systemctl status slapd` or `ps aux | grep ldap`
    Affected if LDAP services are running on an affected version - the vulnerability triggers during LDAP operations involving BER encoding
  3. Check macOS OpenLDAP installation
    Run `/usr/bin/ldapsearch -V` or check via Homebrew with `brew list openldap` and note the version
    Affected if macOS versions 11.0-11.7.8, 12.0-12.6.7, or 13.0-13.4 with OpenLDAP installed
  4. Identify NetApp product versions
    For NetApp systems, use the product's web interface or CLI: `system node show` for Clustered Data ONTAP, or check Active IQ Unified Manager, Ontap Tools, or H-series firmware versions via their respective management interfaces
    Affected if Any version of the listed NetApp products is running - all versions are affected according to the advisory
  5. Check for LDAP client usage
    Inspect any application configuration files that connect to LDAP servers (e.g., /etc/ldap.conf, /etc/openldap/ldap.conf, or application-specific configs)
    Affected if Applications connect to LDAP servers running affected OpenLDAP versions, creating potential denial of service risk

You are affected if your system runs OpenLDAP 2.4.x, RHEL 8.0/9.0 with OpenLDAP, vulnerable macOS versions with OpenLDAP, or any version of the listed NetApp products, AND LDAP services are in use.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 11.7.9 / 12.6.8 / 13.5 or later
Fixed in 11.7.912.6.813.5
Interim mitigation

Apply the vendor-supplied patch or update to a patched version of OpenLDAP that fixes the ber_memalloc_x() null pointer handling. Test in a staging environment before production deployment.

Recommended fix Moderate confidence

OpenLDAP 2.4.x latest patch or OpenLDAP 2.5.x/2.6.x (specific fixed version requires vendor advisory confirmation)

  1. For Enterprise Linux systems: Check Red Hat security advisories (access.redhat.com) for CVE-2023-2953 and apply the latest OpenLDAP security update available for your RHEL version
  2. For macOS systems: Apply the latest Apple security update for your macOS version (11.7.9, 12.6.8, or 13.5 and later contain the fix)
  3. For NetApp products (Active IQ Unified Manager, Clustered Data ONTAP, ONTAP Tools): Refer to security.netapp.com advisories and apply vendor-provided patches
  4. For OpenLDAP installations: Upgrade to the latest stable OpenLDAP 2.4.x release or migrate to OpenLDAP 2.5+/2.6+ which contains the fix
  5. Verify the ber_memalloc_x() function no longer causes NULL pointer dereference after applying the update
Caveat Review vendor-specific release notes for potential compatibility changes when upgrading OpenLDAP major versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Enterprise Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-2953 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data