CyberSecBulletin
CVE-2024-32741NVD status: Analyzed

SIMATIC CN 4100: Use of Hard-coded Password

Published Updated By the CyberSecBulletin desk

CVE-2024-32741 is a critical-severity use of hard-coded password vulnerability in SIMATIC CN 4100 from Siemens, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions V3.0, 3.0 as the first without the flaw, so updating SIMATIC CN 4100 to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update SIMATIC CN 4100 to V3.0 or 3.0, whichever matches your release line, or a later version.
  2. Update Simatic Cn 4100 Firmware to 3.0 or a later version.
  3. Read the advisory on cert-portal.siemens.com for workarounds and exact fixed builds.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
SiemensSIMATIC CN 4100before V3.0; before 3.0V3.0, 3.0
SiemensSimatic Cn 4100 Firmwarebefore 3.03.0

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (siemens.com).

Official description

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V3.0). The affected device contains hard coded password which is used for the privileged system user `root` and for the boot loader `GRUB` by default . An attacker who manages to crack the password hash gains root access to the device.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Hard-coded Password

The product contains a hard-coded password, which it uses for its own inbound authentication or for outbound authentication to external components.

How developers prevent this class of flaw

  • For outbound authentication: store passwords outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible.
  • For inbound authentication: Rather than hard-code a default username and password for first time logins, utilize a first login mode that requires the user to enter a unique strong password.
  • Perform access control checks and limit which entities can access the feature that requires the hard-coded password. For example, a feature might only be enabled through the system console instead of through a network connection.

More Use of Hard-coded Password vulnerabilities (CWE-259)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in SIMATIC CN 4100

All SIMATIC CN 4100 vulnerabilities

Recent Use of Hard-coded Password vulnerabilities

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