CVE-2020-36223

A flaw was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Values Return Filter control handling, resulting in denial of service (double free and out-of-bounds read).

Published: 2021-01-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-36223 is rated High Risk (67.4/100): CVSS High severity, with high exploitation likelihood (EPSS 10.57%, 93th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +4.70% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-36223

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-19 5.87% 10.57% +4.70%
2 2026-05-05 6.67% 5.87% -0.80%
3 2026-01-15 — 6.67% —

Full EPSS history (37 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-36223

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-36223

OS Trackers for CVE-2020-36223

vendor priority summary link
alpine high CVE-2020-36223: 1 source package rows (openldap); 35 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 28. https://security.alpinelinux.org/vuln/CVE-2020-36223
debian not yet assigned CVE-2020-36223 not yet assigned priority: Debian including 1 source packages (openldap), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-36223
redhat medium — https://access.redhat.com/security/cve/CVE-2020-36223
suse high CVE-2020-36223 severity important: SUSE including 443 source package names (0.1.0:libldap-2_4-2-2.4.46-9.48.1, 0.1.0:libldap-data-2.4.46-9.48.1, …), 814 product×package rows across 144 product lines (Container bci/dotnet-aspnet, Container bci/dotnet-runtime, … (144 product lines)): Fixed 679, Known Affected 135. https://www.suse.com/security/cve/CVE-2020-36223/
ubuntu medium CVE-2020-36223 medium priority: Ubuntu including 1 source packages (openldap), 15 status rows across 15 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, trusty, upstream, xenial): released 15. https://ubuntu.com/security/CVE-2020-36223

Affected software / configurations for CVE-2020-36223

Vendor Product Version Raw CPE
openldap openldap < 2.4.57 cpe:2.3:a:openldap:openldap:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
apple mac_os_x >= 10.14.0, < 10.14.6 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:-:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-004:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-005:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-006:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-007:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-001:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-002:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-003:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-004:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-005:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-006:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-007:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-001:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-002:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-003:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update_2:*:*:*:*:*:*
apple macos >= 11.1, < 11.4 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*

References for CVE-2020-36223

URL Tags
http://seclists.org/fulldisclosure/2021/May/64 Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2021/May/65 Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2021/May/70 Mailing List Third Party Advisory
https://bugs.openldap.org/show_bug.cgi?id=9408 Issue Tracking Vendor Advisory
https://git.openldap.org/openldap/openldap/-/commit/21981053a1195ae1555e23df4d9ac68d34ede9dd Patch Vendor Advisory
https://git.openldap.org/openldap/openldap/-/tags/OPENLDAP_REL_ENG_2_4_57 Release Notes Vendor Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
https://lists.debian.org/debian-lts-announce/2021/02/msg00005.html Mailing List Third Party Advisory
https://security.netapp.com/advisory/ntap-20210226-0002/ Third Party Advisory
https://support.apple.com/kb/HT212529 Third Party Advisory
https://support.apple.com/kb/HT212530 Third Party Advisory
https://support.apple.com/kb/HT212531 Third Party Advisory
https://www.debian.org/security/2021/dsa-4845 Third Party Advisory
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