CVE-2020-25242Network attack vector

Service interruption via crafted TCP packets

Published May 12, 2021 · Updated Aug 4, 2024

Uncontrolled resource consumption in Siemens SIMATIC NET CP 343-1 devices allows remote attackers to interrupt service via TCP port 102. The communication processor mishandles specially crafted packets on that service, but Siemens has not disclosed the exhausted resource or parsing locus. Network access to the port is sufficient; an affected device can require a cold restart to recover, with no reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability1.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Siemens SIMATIC NET CP 343-1 devices allows remote attackers to interrupt service via TCP port 102. The communication processor mishandles specially crafted packets on that service, but Siemens has not disclosed the exhausted resource or parsing locus. Network access to the port is sufficient; an affected device can require a cold restart to recover, with no reported data disclosure or modification.

The record

CVE
CVE-2020-25242
Published
May 12, 2021
Updated
Aug 4, 2024
Vendor
Siemens
Product
SIMATIC NET CP 343-1 Advanced
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 12, 2021CVE 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?

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  1. Affected versionversion=All versions

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · SIMATIC NET CP 343-1 Advancedversion=All versions
Siemens · SIMATIC NET CP 343-1 Standardversion=All versions
Siemens · SIMATIC NET CP 343-1 Leanversion=All versions

Published CVSS scores

7.8NVDAV:N/AC:L/Au:N/C:N/I:N/A:C
7.5NVDCVSS: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-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

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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