CVE-2020-36221
Highopenldap - security update
Published Feb 8, 2021 · Updated Oct 16, 2026 · Also known as ALPINE-CVE-2020-36221, BIT-openldap-2020-36221, DEBIAN-CVE-2020-36221, DLA-2544-1, DSA-4845-1, JLSEC-2026-163, SUSE-SU-2021:0692-1, SUSE-SU-2021:0693-1, SUSE-SU-2021:0723-1, SUSE-SU-2021:14700-1, TR-21-0113, UBUNTU-CVE-2020-36221, USN-4724-1, USN-7698-1
Key Facts
Patch immediately- CVE-2020-36221 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Openldap, Macos (Apple), Mac OS X (Apple) 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 Mac OS X 10.14.6, Macos 11.4, compat-libldap-2_3-0 2.3.37-2.74.26.1.
- 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-2020-36221 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 slapd crashes in the Certificate Exact Assertion processing, resulting in denial of service (schema_init.c serialNumberAndIssuerCheck).
Affected Products
408 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpenldapOpenldap | See advisory | 2.4.57 |
| MacosApple | See advisory | 11.4 |
| Mac OS XApple | 10.14.6, 10.14.6-security_update_2019-004, 10.14.6-security_update_2019-005, 10.14.6-security_update_2019-006, 10.14.6-security_update_2019-007, 10.14.6-security_update_2020-001, 10.14.6-security_update_2020-002, 10.14.6-security_update_2020-003 | 10.14.6 |
| Debian LinuxDebian | 10.0, 9.0 | n/a |
| rootio-openldaprootio | See advisory | 2.4.57+dfsg-1 |
Patched Releases
Mac OS X
10.14.6
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
Timeline
Publicly disclosed
Feb 8, 2021
Last updated
Oct 16, 2026
Weakness Type
- CWE-190 Integer Overflow or Wraparound
- 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://bugzilla.suse.com/1182279
- advisoryhttps://bugzilla.suse.com/1182408
- advisoryhttps://bugzilla.suse.com/1182411
FAQ
Common Questions.
An integer underflow was discovered in OpenLDAP before 2.4.57 leading to slapd crashes in the Certificate Exact Assertion processing, resulting in denial of service (schema_init.c serialNumberAndIssuerCheck).
Affected: Openldap; Macos (Apple); Mac OS X (Apple) versions 10.14.6, 10.14.6-security_update_2019-004, 10.14.6-security_update_2019-005, 10.14.6-security_update_2019-006, 10.14.6-security_update_2019-007, 10.14.6-security_update_2020-001, 10.14.6-security_update_2020-002, 10.14.6-security_update_2020-003, 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 Mac OS X 10.14.6, Macos 11.4, compat-libldap-2_3-0 2.3.37-2.74.26.1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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