CVE-2023-35920Network attack vector

Remote service halt via crafted IP packets

Published Jul 11, 2023 · Updated Nov 12, 2024

Denial of service in Siemens SIMATIC MV500 devices before 3.3.4 allows remote attackers to halt operation using crafted IP packets. Siemens identifies the IP-packet processing path as the affected locus but has not disclosed the specific parser or resource-handling error. No authentication or user interaction is required; successful exploitation leaves the reader unavailable until it is restarted manually.

CVSS severity7.5
High
EPSS probability0.87%
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 Siemens SIMATIC MV500 devices before 3.3.4 allows remote attackers to halt operation using crafted IP packets. Siemens identifies the IP-packet processing path as the affected locus but has not disclosed the specific parser or resource-handling error. No authentication or user interaction is required; successful exploitation leaves the reader unavailable until it is restarted manually.

The record

CVE
CVE-2023-35920
Published
Jul 11, 2023
Updated
Nov 12, 2024
Vendor
Siemens
Product
SIMATIC MV550 H
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 12, 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=0 <V3.3.4
  2. Affected versionversion=All versions < V3.3.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · SIMATIC MV550 Hversion=0 <V3.3.4; version=All versions < V3.3.4
Siemens · SIMATIC MV540 Sversion=0 <V3.3.4; version=All versions < V3.3.4
Siemens · SIMATIC MV560 Uversion=0 <V3.3.4; version=All versions < V3.3.4
Siemens · SIMATIC MV560 Xversion=0 <V3.3.4; version=All versions < V3.3.4
Siemens · SIMATIC MV550 Sversion=0 <V3.3.4; version=All versions < V3.3.4
Siemens · SIMATIC MV540 Hversion=0 <V3.3.4; version=All versions < V3.3.4

Published CVSS scores

7.5Siemens AGCVSS: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 exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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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