CVE-2024-46304Network attack vector

Remote server crash via block-wise PUT handling

Published Oct 9, 2024 · Updated Oct 10, 2024

NULL pointer dereference in libcoap 4.3.5-rc2 and earlier allows remote attackers to crash CoAP servers via block-wise PUT requests. The coap_handle_request_put_block function reads through an invalid near-null pointer while processing a PUT request that uses block-wise transfer. A reachable server with block-wise PUT handling exposed must process a triggering request sequence; the published reproduction required hours of fuzzing and caused a process crash.

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 4.3.5-rc2 and earlier allows remote attackers to crash CoAP servers via block-wise PUT requests. The coap_handle_request_put_block function reads through an invalid near-null pointer while processing a PUT request that uses block-wise transfer. A reachable server with block-wise PUT handling exposed must process a triggering request sequence; the published reproduction required hours of fuzzing and caused a process crash.

The record

CVE
CVE-2024-46304
Published
Oct 9, 2024
Updated
Oct 10, 2024
Vendor
libcoap
Product
libcoap
Classifications
CWE-120, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 9, 2024CVE publishedPublication date reported by the CVE source.
  2. Oct 10, 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?

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

  1. Affected versionversion=4.3.5-rc2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

libcoap · libcoapversion=4.3.5-rc2

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

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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