CVE-2020-36228
Highopenldap - security update
Published Feb 8, 2021 · Updated Oct 16, 2026 · Also known as ALPINE-CVE-2020-36228, BIT-openldap-2020-36228, DEBIAN-CVE-2020-36228, JLSEC-2026-170, UBUNTU-CVE-2020-36228
Key Facts
Patch immediately- CVE-2020-36228 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Openldap, Macos (Apple), Debian Linux and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 85% probability of exploitation in the next 30 days.
- Fixed versions are available, including Macos 11.4, compat-libldap-2_3-0 2.3.37-2.74.26.1, compat-libldap-2_3-0 2.3.37-39.1.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
85%
Higher than 99.7% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
Get the full CVE-2020-36228 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
An integer underflow was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Certificate List Exact Assertion processing, resulting in denial of service.
Affected Products
390 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpenldapOpenldap | See advisory | 2.4.57 |
| MacosApple | See advisory | 11.4 |
| Debian LinuxDebian | 10.0, 9.0 | n/a |
| rootio-openldaprootio | See advisory | 2.4.57+dfsg-1 |
| ldap-utilsubuntu | See advisory | 2.4.31-1+nmu2ubuntu8.5+esm7 |
Patched Releases
Macos
11.4
compat-libldap-2_3-0
2.3.37-2.74.26.1, 2.3.37-39.1
ldap-utils
2.4.31-1+nmu2ubuntu8.5+esm7
libldap-2_4-2
2.4.26-0.74.26.1, 2.4.41-18.83.1, 2.4.46-9.48.1, 2.4.46-lp152.14.18.1
libldap-2_4-2-32bit
2.4.26-0.74.26.1, 2.4.41-18.83.1, 2.4.46-9.48.1, 2.4.46-lp152.14.18.1
libldap-2.4-2
2.4.31-1+nmu2ubuntu8.5+esm7
libldap-data
2.4.46-9.48.1, 2.4.46-lp152.14.18.1
libldap-openssl1-2_4-2
2.4.26-0.74.26.1
libldap-openssl1-2_4-2-32bit
2.4.26-0.74.26.1
libldap-openssl1-2_4-2-x86
2.4.26-0.74.26.1
libldap2-dev
2.4.31-1+nmu2ubuntu8.5+esm7
Openldap
2.4.31-1+nmu2ubuntu8.5+esm7, 2.4.40-16.36.amzn1, 2.4.42+dfsg-2ubuntu3.12, 2.4.44-25.amzn2.0.5, 2.4.44+dfsg-5+deb9u7, 2.4.45+dfsg-1ubuntu1.9, 2.4.47+dfsg-3+deb10u5, 2.4.49+dfsg-2ubuntu1.6, 2.4.57, 2.4.57-1, 2.4.57-1.ph1, 2.4.57-1.ph2, 2.4.57-1.ph3, 2.4.57-1.ph4, 2.4.57-2, 2.4.57-r0, 2.4.57+dfsg-1
openldap-clients
2.4.40-16.36.amzn1, 2.4.44-25.amzn2.0.5
openldap-devel
2.4.40-16.36.amzn1, 2.4.44-25.amzn2.0.5
openldap-servers
2.4.40-16.36.amzn1, 2.4.44-25.amzn2.0.5
openldap-servers-sql
2.4.40-16.36.amzn1, 2.4.44-25.amzn2.0.5
openldap2
2.4.26-0.74.26.1, 2.4.41-18.83.1, 2.4.41-39.1, 2.4.46-9.48.1, 2.4.46-lp152.14.18.1
openldap2-back-meta
2.4.26-0.74.26.1, 2.4.41-18.83.1, 2.4.46-9.48.1, 2.4.46-lp152.14.18.1
openldap2-back-perl
2.4.41-18.83.1, 2.4.46-9.48.1, 2.4.46-lp152.14.18.1
openldap2-back-sock
2.4.46-lp152.14.18.1
openldap2-back-sql
2.4.46-lp152.14.18.1
openldap2-client
2.4.26-0.74.26.1, 2.4.41-18.83.1, 2.4.46-9.48.1, 2.4.46-lp152.14.18.1
openldap2-client-openssl1
2.4.26-0.74.26.1
openldap2-contrib
2.4.46-lp152.14.18.1
openldap2-devel
2.4.41-18.83.1, 2.4.46-9.48.1, 2.4.46-lp152.14.18.1
Timeline
Publicly disclosed
Feb 8, 2021
Last updated
Oct 16, 2026
Weakness Type
- CWE-191 Integer Underflow (Wrap or Wraparound)
References
- advisoryhttps://bugs.openldap.org/show_bug.cgi?id=9404
- advisoryhttps://bugs.openldap.org/show_bug.cgi?id=9424
- advisoryhttps://bugs.openldap.org/show_bug.cgi?id=9427
- advisoryhttps://bugzilla.suse.com/1182279
- advisoryhttps://bugzilla.suse.com/1182408
FAQ
Common Questions.
An integer underflow was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Certificate List Exact Assertion processing, resulting in denial of service.
Affected: Openldap; Macos (Apple); Debian Linux versions 10.0, 9.0, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Macos 11.4, compat-libldap-2_3-0 2.3.37-2.74.26.1, compat-libldap-2_3-0 2.3.37-39.1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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