CVE-2023-28766Network attack vector

Unauthenticated device crash via malformed HTTP parameters

Published Apr 11, 2023 · Updated Nov 11, 2025

Null pointer dereference in the Siemens SIPROTEC 5 hosted web service allows remote attackers to crash affected devices via HTTP. The service fails to validate HTTP request parameters and dereferences a resulting null pointer while processing specially crafted packets. No authentication or user interaction is required; network access to TCP port 4443 is sufficient to interrupt the target device.

CVSS severity7.5
High
EPSS probability0.94%
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 the Siemens SIPROTEC 5 hosted web service allows remote attackers to crash affected devices via HTTP. The service fails to validate HTTP request parameters and dereferences a resulting null pointer while processing specially crafted packets. No authentication or user interaction is required; network access to TCP port 4443 is sufficient to interrupt the target device.

The record

CVE
CVE-2023-28766
Published
Apr 11, 2023
Updated
Nov 11, 2025
Vendor
Siemens
Product
SIPROTEC 5 6MD86 (CP300)
Classifications
CWE-476, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 11, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=V7.80 <V9.40

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · SIPROTEC 5 6MD86 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SJ85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7UT85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SJ82 (CP150)version=0 <V9.40
Siemens · SIPROTEC 5 7SD82 (CP100)version=0 <V8.90
Siemens · SIPROTEC 5 7SA86 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7UT82 (CP100)version=0 <V8.90
Siemens · SIPROTEC 5 7SS85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SJ81 (CP150)version=0 <V9.40
Siemens · SIPROTEC 5 7VE85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 Communication Module ETH-BD-2FOversion=0 <V9.40
Siemens · SIPROTEC 5 7SL82 (CP100)version=0 <V8.90
Siemens · SIPROTEC 5 7UT87 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 6MD85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7VU85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 6MD89 (CP300)version=V7.80 <V9.64
Siemens · SIPROTEC 5 7ST85 (CP300)version=V7.80 <V9.64
Siemens · SIPROTEC 5 Compact 7SX800 (CP050)version=0 <V9.40
Siemens · SIPROTEC 5 7SD86 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7UM85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SJ81 (CP100)version=0 <V8.89
Siemens · SIPROTEC 5 7VK87 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SL86 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SA87 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SL87 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SJ82 (CP100)version=0 <V8.89
Siemens · SIPROTEC 5 7SJ86 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7UT82 (CP150)version=0 <V9.40
Siemens · SIPROTEC 5 7SA82 (CP150)version=0 <V9.40
Siemens · SIPROTEC 5 Communication Module ETH-BA-2EL (Rev.1)version=0 <V8.89; version=0 <V9.40
Siemens · SIPROTEC 5 7SD82 (CP150)version=0 <V9.40
Siemens · SIPROTEC 5 7SA82 (CP100)version=0 <V8.90
Siemens · SIPROTEC 5 Communication Module ETH-BB-2FO (Rev.1)version=0 <V8.89; version=0 <V9.40
Siemens · SIPROTEC 5 7SL82 (CP150)version=0 <V9.40
Siemens · SIPROTEC 5 6MU85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SK82 (CP150)version=0 <V9.40
Siemens · SIPROTEC 5 7SX85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SK85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7ST86 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SK82 (CP100)version=0 <V8.89
Siemens · SIPROTEC 5 7KE85 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7UT86 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SD87 (CP300)version=V7.80 <V9.40
Siemens · SIPROTEC 5 7SX82 (CP150)version=0 <V9.40

Published CVSS scores

7.5INCIBE-CERTCVSS: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 exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T0814Denial 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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