CVE-2023-51391Public exploitNetwork attack vector

Device crash via unchecked header delimiter lookup

Published Apr 16, 2024 · Updated Feb 13, 2025

Denial of service in Micrium OS Network HTTP Server in Gecko SDK before 4.4.2 allows remote attackers to crash devices via malformed HTTP headers. HTTPsReq_HdrParseValGet increments the unchecked NULL result from Str_Char_N when a header lacks a colon, then HTTP_StrGraphSrchFirst dereferences address 1. No authentication or user interaction is required; exploitation interrupts the device, and systems mapping address 1 can experience further memory corruption.

CVSS severity7.5
High
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Micrium OS Network HTTP Server in Gecko SDK before 4.4.2 allows remote attackers to crash devices via malformed HTTP headers. HTTPsReq_HdrParseValGet increments the unchecked NULL result from Str_Char_N when a header lacks a colon, then HTTP_StrGraphSrchFirst dereferences address 1. No authentication or user interaction is required; exploitation interrupts the device, and systems mapping address 1 can experience further memory corruption.

The record

CVE
CVE-2023-51391
Published
Apr 16, 2024
Updated
Feb 13, 2025
Vendor
Sigma Designs
Product
Gecko SDK
Classifications
CWE-125, CWE-476, CAPEC-469, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 16, 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=0 <4.4.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Sigma Designs · Gecko SDKversion=0 <4.4.2
Silicon Laboratories · Gecko SDKversion=0 <4.4.2

Published CVSS scores

7.5Silicon LabsCVSS: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 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-125Out-of-bounds Read
CWE-476NULL Pointer Dereference
CAPEC-469HTTP DoS
T1499.004Application or System Exploitation

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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