CVE-2026-22925

SIMATIC CN 4100 TCP SYN Flood Denial of Service

View on CVE.org
Published May 12, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V5.0). The affected application is susceptible to resource exhaustion when subjected to high volume of TCP SYN packets
This could allow an attacker to render the service unavailable and cause denial-of-service conditions by overwhelming system resources.

Analysis

AI-generated

Technical impact

A vulnerability in the SIMATIC CN 4100 allows an attacker to trigger resource exhaustion by sending a high volume of TCP SYN packets. This leads to denial of service, effectively rendering the system unavailable. The weakness is a classic instance of resource exhaustion, cataloged as CWE-770.

Affected Systems

Siemens SIMATIC CN 4100 (all versions prior to V5.0) are affected by this issue. No specific patch version is provided in the advisory; a firmware upgrade to V5.0 or later would remove the vulnerability.

Risk and Exploitability

The CVSS score of 8.7 indicates a high severity risk. EPSS is not available, and the vulnerability is not listed in the CISA KEV catalog, suggesting no currently known active exploitation. The attack vector is likely network-based: an adversary could launch a TCP SYN flood from outside the local network to overwhelm the controller's resources. Given the lack of an official workaround, administrators should treat this as a priority threat if the device is exposed to external networks.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update SIMATIC CN 4100 to version V5.0 or later to eliminate the vulnerability.
  • Configure network filtering or rate limiting to reduce the impact of high-volume SYN packets.
  • Deploy DoS protection mechanisms such as SYN cookies or a traffic shaper to mitigate resource exhaustion.

Generated by OpenCVE AI on May 12, 2026 at 10:24 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}
Type Values Removed Values Added
First Time appeared Siemens
Siemens simatic Cn 4100
Vendors & Products Siemens
Siemens simatic Cn 4100
Type Values Removed Values Added
Title SIMATIC CN 4100 TCP SYN Flood Denial of Service
Type Values Removed Values Added
Description A vulnerability has been identified in SIMATIC CN 4100 (All versions < V5.0). The affected application is susceptible to resource exhaustion when subjected to high volume of TCP SYN packets This could allow an attacker to render the service unavailable and cause denial-of-service conditions by overwhelming system resources.
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}
Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling

Sources

Status
PUBLISHED
Assigner
siemens
Published
Updated
May 12, 2026, 1:27 PM
Reserved
Jan 13, 2026, 3:21 PM

View source JSON

Updated
May 12, 2026, 1:27 PM

JSON

Status
Analyzed
Published
May 12, 2026, 10:16 AM
Modified
Oct 24, 2026, 1:10 PM

View source JSON

No data.

Updated
May 12, 2026, 10:45 AM

JSON