CVE-2023-51847Public exploitNetwork attack vector

Remote server crash via null context dereference

Published Jun 6, 2024 · Updated Feb 13, 2025

Null-pointer dereference in libcoap a3ed466 allows remote attackers to crash a CoAP server through a resource deletion request. The thread-safe coap_delete_resource wrapper locks its caller-supplied context before deriving the owning context from the resource, so a null argument is dereferenced. The affected development snapshot requires thread-safe server support, and a reachable deletion handler lets an unauthenticated request terminate the server process.

CVSS severity7.5
High
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Null-pointer dereference in libcoap a3ed466 allows remote attackers to crash a CoAP server through a resource deletion request. The thread-safe coap_delete_resource wrapper locks its caller-supplied context before deriving the owning context from the resource, so a null argument is dereferenced. The affected development snapshot requires thread-safe server support, and a reachable deletion handler lets an unauthenticated request terminate the server process.

The record

CVE
CVE-2023-51847
Published
Jun 6, 2024
Updated
Feb 13, 2025
Vendor
libcoap
Product
libcoap
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 6, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=v.a3ed466

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

libcoap · libcoapversion=v.a3ed466

Published CVSS scores

7.5CISA ADPCVSS: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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
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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