How severe is CVE-2023-51440?

CVE-2023-51440 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-51440 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-51440?

CVE-2023-51440 primarily affects Siemens Simatic Cp 343-1 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-51440?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2023-51440 have an EU (EUVD) identifier?

Yes. CVE-2023-51440 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-56160.

When was CVE-2023-51440 published?

CVE-2023-51440 was published on 2024-02-13 and last updated on 2026-06-17.

CVE-2023-51440

CVE-2023-51440 is a high-severity vulnerability in Siemens Simatic Cp 343-1 Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-940.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2023-56160
Weakness: CWE-940
Affected product: Siemens Simatic Cp 343-1 Firmware
Published: 2024-02-13
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2023-51440?: 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.
How severe is CVE-2023-51440?: CVE-2023-51440 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-51440 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-51440?: CVE-2023-51440 primarily affects Siemens Simatic Cp 343-1 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-51440?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2023-51440 have an EU (EUVD) identifier?: Yes. CVE-2023-51440 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-56160.
When was CVE-2023-51440 published?: CVE-2023-51440 was published on 2024-02-13 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/html/ssa-516818.html

Affected products (4)

cpe:2.3:o:siemens:simatic_cp_343-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_cp_343-1_lean_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:siplus_net_cp_343-1_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:siplus_net_cp_343-1_lean_firmware:-:*:*:*:*:*:*:*

More vulnerabilities in Siemens Simatic Cp 343-1 Firmware

CVE-2015-8214 — Critical (CVSS 9.7): A vulnerability has been identified in SIMATIC NET CP 342-5 (incl. SIPLUS variants) (All versions), SIMATIC NET CP…
CVE-2016-8673 — High (CVSS 8.8): A vulnerability has been identified in SIMATIC CP 343-1 Advanced (incl. SIPLUS NET variant) (All versions < V3.0.53),…
CVE-2021-33737 — High (CVSS 7.5): A vulnerability has been identified in SIMATIC CP 343-1 (incl. SIPLUS variants) (All versions), SIMATIC CP 343-1…
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CVE-2016-8672 — Medium (CVSS 5.3): A vulnerability has been identified in SIMATIC CP 343-1 Advanced (incl. SIPLUS NET variant) (All versions < V3.0.53),…

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