CVE-2021-41545Network attack vector

Service interruption via uncaught BACnet packet exception

Published May 10, 2022 · Updated Aug 4, 2024

Uncaught exception in Siemens Desigo DXR2 and PXC controllers allows remote attackers to disable BACnet communications via a crafted packet. The BACnet packet handler leaves its communication function in an out-of-work state when a specific protocol packet raises an exception that remains uncaught. Unauthenticated network access to BACnet is sufficient, and successful exploitation interrupts controller communications and can reset the device to its factory state.

CVSS severity7.5
High
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncaught exception in Siemens Desigo DXR2 and PXC controllers allows remote attackers to disable BACnet communications via a crafted packet. The BACnet packet handler leaves its communication function in an out-of-work state when a specific protocol packet raises an exception that remains uncaught. Unauthenticated network access to BACnet is sufficient, and successful exploitation interrupts controller communications and can reset the device to its factory state.

The record

CVE
CVE-2021-41545
Published
May 10, 2022
Updated
Aug 4, 2024
Vendor
Siemens
Product
Desigo PXC5
Classifications
CWE-248, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 10, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=All versions < V02.20.142.10-10884

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · Desigo PXC5version=All versions < V02.20.142.10-10884
Siemens · Desigo PXC3version=All versions < V01.21.142.4-18
Siemens · Desigo PXC4version=All versions < V02.20.142.10-10884
Siemens · Desigo DXR2version=All versions < V01.21.142.5-22

Published CVSS scores

7.5NIST NVDCVSS: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-248Uncaught Exception
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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