PatchTheCVECVE-2023-2953: A vulnerability was found in openldap
56
This month
HIGH 7.5REMOTEWATCHLISTDOWNGRADEMITIGATEUPGRADE
CVE-2023-2953 is a high-severity flaw (CVSS 7.5) affecting openldap, enterprise linux, macos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
A vulnerability was found in openldap. This security flaw causes a null pointer dereference in ber_memalloc_x() function.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 2.0% (top 19%) |
| CISA exploited list | No |
| Weakness | CWE-476 |
| Published | 2023-05-30 |
| Last modified | 2026-10-14 |
Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
openldap openldap DOWNGRADE
Affected: 2.4
Fixed in: no fixed release known
Safe to downgrade to: a release before 2.4
1. Check installed version
apt-cache policy openldap || rpm -q openldap || openldap --version
2. No fixed release: DOWNGRADE to a release before 2.4 (Debian / Ubuntu)
apt-cache madison openldap
sudo apt install openldap=<VERSION_BEFORE_2.4>
sudo apt-mark hold openldap
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list openldap
sudo dnf downgrade openldap-<VERSION_BEFORE_2.4>
sudo dnf versionlock add openldap
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
redhat enterprise linux MITIGATE
Affected: 8.0 · 9.0
Fixed in: no fixed release known
Safe to downgrade to: a release before 8.0
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
apple macos UPGRADE
Affected: >= 11.0 and < 11.7.9 · >= 12.0 and < 12.6.8 · >= 13.0 and < 13.5
Fixed in: 11.7.9, 12.6.8, 13.5
Safe to downgrade to: a release before 11.0
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
netapp active iq unified manager MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy active-iq-unified-manager || rpm -q active-iq-unified-manager || active-iq-unified-manager --version
No fixed or unaffected release known
Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.
netapp clustered data ontap MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy clustered-data-ontap || rpm -q clustered-data-ontap || clustered-data-ontap --version
No fixed or unaffected release known
Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.
netapp ontap tools MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy ontap-tools || rpm -q ontap-tools || ontap-tools --version
No fixed or unaffected release known
Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2023-2953?
openldap: downgrade or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation; macos: upgrade to 11.7.9, 12.6.8, 13.5. Exact commands for each OS are on this page.
Is CVE-2023-2953 being exploited?
CVE-2023-2953 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2023-2953 affect?
CVE-2023-2953 affects openldap, enterprise linux, macos. Severity is high (CVSS 7.5). A vulnerability was found in openldap. This security flaw causes a null pointer dereference in ber_memalloc_x() function.
How urgent is CVE-2023-2953?
Priority 56/100. High severity; Remotely exploitable, no login, no user action; On your watchlist
Software pages
macOS vulnerabilities · OpenLDAP vulnerabilities
Related CVEs
- CVE-2022-29155 CRITICAL 9.8 UPGRADE MITIGATE In OpenLDAP 2.x before 2.5.12 and 2.6.x before 2.6.2, a SQL injection vulnerability exists in the experimental
- CVE-2021-27212 HIGH 7.5 UPGRADE MITIGATE In OpenLDAP through 2.4.57 and 2.5.x through 2.5.1alpha, an assertion failure in slapd can occur in the issuer
- CVE-2020-36230 HIGH 7.5 UPGRADE MITIGATE A flaw was discovered in OpenLDAP before 2.4.57 leading in an assertion failure in slapd in the X.509 DN parsi
- CVE-2020-36229 HIGH 7.5 UPGRADE MITIGATE A flaw was discovered in ldap_X509dn2bv in OpenLDAP before 2.4.57 leading to a slapd crash in the X.509 DN par
- CVE-2020-36228 HIGH 7.5 UPGRADE MITIGATE An integer underflow was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Certificate List