Simatic Cn 4100 FirmwareOperating system · Siemens

CVE-2023-49251

HIGH · 8.8 CVSS v3.1 Published 2024-01-09
Fix available
A fix is available. Upgrade to 2.7 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.7). The "intermediate installation" system state of the affected application allows an attacker to add their own login credentials to the device. This allows an attacker to remotely login as root and take control of the device even after the affected device is fully set up.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-639

The application uses a user-supplied identifier to look up a record without checking that the requester actually owns it, so changing the identifier in a request returns someone else's data. This is the classic insecure-direct-object-reference — the change-the-ID-in-the-URL bug. Remediation is authorizing every object access against the acting user, not merely confirming they are logged in.

General guidance for the authorization bypass (idor) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Simatic Cn 4100 FirmwareOperating system
Affected:< 2.7

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.7 or later
Fixed in 2.7
Recommended fix High confidence

V2.7

  1. Download the V2.7 firmware update for SIMATIC CN 4100 from the official Siemens support portal (support.industry.siemens.com)
  2. Review the firmware upgrade instructions in the Siemens product documentation before proceeding
  3. Connect to the SIMATIC CN 4100 device via the recommended management interface
  4. Back up the current device configuration as recommended in the Siemens administration manual
  5. Upload and install the V2.7 firmware to the device following the standard Siemens firmware update procedure
  6. After the firmware upgrade completes, verify the device is running V2.7 or later
  7. Confirm the vulnerability is remediated by verifying that the intermediate installation state no longer allows credential injection
  8. Ensure the device is properly reconfigured according to your network security policies after the update
Caveat Review Siemens release notes for V2.7 for any functionality changes or compatibility considerations before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-49251 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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