CVE-2020-36229Public exploitNetwork attack vector

Unauthenticated slapd crash via malformed X.509 DN

Published Jan 25, 2021 · Updated Aug 4, 2024

Type confusion in OpenLDAP before 2.4.57 allows remote attackers to crash slapd with a crafted unauthenticated LDAP packet. ldap_X509dn2bv fails to reject X.509 distinguished-name structures whose RDN boundary exceeds the enclosing DN or whose tags cannot be decoded, allowing malformed values to reach ad_keystring. Network access to slapd is sufficient; exploitation requires no credentials or user interaction and interrupts the directory service without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability4.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in OpenLDAP before 2.4.57 allows remote attackers to crash slapd with a crafted unauthenticated LDAP packet. ldap_X509dn2bv fails to reject X.509 distinguished-name structures whose RDN boundary exceeds the enclosing DN or whose tags cannot be decoded, allowing malformed values to reach ad_keystring. Network access to slapd is sufficient; exploitation requires no credentials or user interaction and interrupts the directory service without reported data disclosure or modification.

The record

CVE
CVE-2020-36229
Published
Jan 25, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-843, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 25, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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