CVE-2023-51440

highpriority · track · 30EPSS 0.006 · 48 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.60% (48th) EPSS
CVSS 7.5 · high
Is it mine?
28 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cisa_csaf_ot

EPSS · scored 2026-10-27

A vulnerability has been identified in SIMATIC CP 343-1 (6GK7343-1EX30-0XE0) (All versions), SIMATIC CP 343-1 Lean (6GK7343-1CX10-0XE0) (All versions), SIPLUS NET CP 343-1 (6AG1343-1EX30-7XE0) (All versions), SIPLUS NET CP 343-1 Lean (6AG1343-1CX10-2XE0) (All versions). Affected products incorrectly validate TCP sequence numbers. This could allow an unauthenticated remote attacker to create a denial of service condition by injecting spoofed TCP RST packets.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

No vendor fix yet; a workaround is available.

  • WorkaroundSIMATIC CP 343-1 (6GK7343-1EX30-0XE0)siemens_psirt

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • WorkaroundSIMATIC CP 343-1 Lean (6GK7343-1CX10-0XE0)siemens_psirt

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • WorkaroundSIPLUS NET CP 343-1 (6AG1343-1EX30-7XE0)siemens_psirt

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • WorkaroundSIPLUS NET CP 343-1 Lean (6AG1343-1CX10-2XE0)siemens_psirt

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • WorkaroundSIMATIC CP 343-1 (6GK7343-1EX30-0XE0)cisa_csaf_ot

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • WorkaroundSIMATIC CP 343-1 Lean (6GK7343-1CX10-0XE0)cisa_csaf_ot

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • WorkaroundSIPLUS NET CP 343-1 (6AG1343-1EX30-7XE0)cisa_csaf_ot

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • WorkaroundSIPLUS NET CP 343-1 Lean (6AG1343-1CX10-2XE0)cisa_csaf_ot

    Apply network segmentation and Defense-in-Depth practices to reduce likelihood of a threat actor to be able to reach a potentially vulnerable device

  • No fix plannedSIMATIC CP 343-1 (6GK7343-1EX30-0XE0)siemens_psirt

    Currently no fix is planned

  • No fix plannedSIMATIC CP 343-1 Lean (6GK7343-1CX10-0XE0)siemens_psirt

    Currently no fix is planned

  • No fix plannedSIPLUS NET CP 343-1 (6AG1343-1EX30-7XE0)siemens_psirt

    Currently no fix is planned

  • No fix plannedSIPLUS NET CP 343-1 Lean (6AG1343-1CX10-2XE0)siemens_psirt

    Currently no fix is planned

  • No fix plannedSIMATIC CP 343-1 (6GK7343-1EX30-0XE0)cisa_csaf_ot

    Currently no fix is planned

  • No fix plannedSIMATIC CP 343-1 Lean (6GK7343-1CX10-0XE0)cisa_csaf_ot

    Currently no fix is planned

  • No fix plannedSIPLUS NET CP 343-1 (6AG1343-1EX30-7XE0)cisa_csaf_ot

    Currently no fix is planned

  • No fix plannedSIPLUS NET CP 343-1 Lean (6AG1343-1CX10-2XE0)cisa_csaf_ot

    Currently no fix is planned

02

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:T/RC:Csecondary · CISA US
v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:T/RC:Csecondary · ENISA EU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · productcert@siemens.com DEexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:T/RC:Csecondary · Siemens ProductCERT DE
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-940USCWE-940USCWE-940USCWE-940US
05

affected products (28)

Products and version ranges known to be affected.

showing 20 of 28
06

advisories (2)

Vendor and ecosystem advisories describing this.

  • SSA-516818SSA-516818: TCP Sequence Number Validation Vulnerability in the TCP/IP Stack of CP343-1 Devices2024-02-13csaf · siemens_psirtDE

    Affected products incorrectly validate TCP sequence numbers. This could allow an unauthenticated remote attacker to create a denial of service condition by injecting spoofed TCP RST packets. Siemens recommends countermeasures for products where fixes are not, or not yet available.

  • ICSA-24-046-04Siemens CP343-1 Devices2024-02-13icsa · cisa_csaf_otUS

    Affected products incorrectly validate TCP sequence numbers. This could allow an unauthenticated remote attacker to create a denial of service condition by injecting spoofed TCP RST packets. Siemens recommends countermeasures for products where fixes are not, or not yet available.

07

also known as (5)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisa_csaf_otsiemens_psirtNVDCVE.orgMITRE
published 2024-02-13modified 2026-06-17
09

references (4)

External citations — patches, advisories, analysis.

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