CVE-2023-29131: A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.5)

Q: How do I fix CVE-2023-29131?

simatic cn 4100 firmware: upgrade to 2.5. Exact commands for each OS are on this page.

Q: Is CVE-2023-29131 being exploited?

CVE-2023-29131 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-29131 affect?

CVE-2023-29131 affects simatic cn 4100 firmware. Severity is high (CVSS 7.4). A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.5). Affected device consists of an incorrect default value in the SSH configuration. This could allow an attacker to bypass network isolation.

Routine

HIGH 7.4UPGRADE

CVE-2023-29131 is a high-severity flaw (CVSS 7.4) affecting simatic cn 4100 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.5). Affected device consists of an incorrect default value in the SSH configuration. This could allow an attacker to bypass network isolation.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.4 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-276
Published	2023-07-11
Last modified	2026-10-24

Publisher (CNA): Siemens AG · Vendor: siemens

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-07-11 10:15 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

siemens simatic cn 4100 firmware UPGRADE

Affected: < 2.5

Fixed in: 2.5

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

Fedora 46 · sugar-toolkit-gtk3 · FIXED · 0.122-2.fc46 · FEDORA-2026-d11eb2faf0 · source

sudo dnf upgrade --advisory=FEDORA-2026-d11eb2faf0

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-29131?

simatic cn 4100 firmware: upgrade to 2.5. Exact commands for each OS are on this page.

Is CVE-2023-29131 being exploited?

CVE-2023-29131 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-29131 affect?

CVE-2023-29131 affects simatic cn 4100 firmware. Severity is high (CVSS 7.4). A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.5). Affected device consists of an incorrect default value in the SSH configuration. This could allow an attacker to bypass network isolation.

How urgent is CVE-2023-29131?

Priority 35/100. High severity

Software pages

Siemens vulnerabilities

Related CVEs

CVE-2026-22925 HIGH 7.5 UPGRADE A vulnerability has been identified in SIMATIC CN 4100 (All versions < V5.0)
CVE-2025-40937 HIGH 8.3 UPGRADE A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1)
CVE-2025-40938 HIGH 8.1 UPGRADE A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1)
CVE-2025-40940 MEDIUM 4.9 UPGRADE A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1)
CVE-2025-40941 MEDIUM 4.3 UPGRADE A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1)

References

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