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Vc4Application · Br Automation

CVE-2023-1617

CRITICAL · 9.8 CVSS v3.1 Published 2023-04-14
Fix available
A fix is available. Upgrade to 3.96.8 / 4.34.7 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
Improper Authentication vulnerability in B&R Industrial Automation B&R VC4 (VNC-Server modules).  This vulnerability may allow an unauthenticated network-based attacker to bypass the authentication mechanism of the VC4 visualization on affected devices. The impact of this vulnerability depends on the functionality provided in the visualization. This issue affects B&R VC4: from 3.* through 3.96.7, from 4.0* through 4.06.7, from 4.1* through 4.16.3, from 4.2* through 4.26.8, from 4.3* through 4.34.6, from 4.4* through 4.45.1, from 4.5* through 4.45.3, from 4.7* through 4.72.9.

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 · high confidence

Improper authentication bypass vulnerability in B&R VC4 VNC-Server modules allows unauthenticated network attackers to bypass the authentication mechanism of the VC4 visualization. The vulnerability affects multiple version branches (3.x, 4.0-4.7.x) of the visualization server, potentially granting unauthorized access to industrial process controls and HMI functionality.

MitigationUpgrade B&R VC4 to a patched version beyond the affected ranges. As an interim measure, isolate VC4 VNC services behind network segmentation and restrict access to essential only, as the CVSS 9.8 indicates trivial network exploitation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
Vc4Application
Affected:< 3.96.8>= 4.0.0, <= 4.06.4>= 4.10.0, <= 4.16.3>= 4.20.0, <= 4.26.8>= 4.30.0, < 4.34.7>= 4.40.0, <= 4.45.1>= 4.50.0, <= 4.53.0>= 4.70.0, < 4.73.0

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify VC4 installation
    Check installed programs or B&R software inventory for 'B&R Automation VC4' or 'VC4' visualization components
    Affected if VC4 software is present on the system
  2. Determine VC4 version
    Locate the VC4 version information in the installed software details, registry, or VC4 service properties
    Affected if Installed version falls within any of the affected ranges: < 3.96.8; 4.0.0-4.06.4; 4.10.0-4.16.3; 4.20.0-4.26.8; 4.30.0-4.34.6; 4.40.0-4.45.1; 4.50.0-4.53.0; 4.70.0-4.72.x
  3. Confirm VNC-Server module is active
    Check VC4 configuration or running services for the VNC-Server module enabled status
    Affected if VNC-Server module is enabled and listening on network ports (typically 5900+)

System is affected if VC4 with a vulnerable version is installed and the VNC-Server module is enabled, allowing unauthenticated network access to bypass authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 3.96.8 / 4.34.7 / 4.73.0 or later
Fixed in 3.96.84.34.74.73.0
Interim mitigation

Upgrade B&R VC4 to a patched version beyond the affected ranges. As an interim measure, isolate VC4 VNC services behind network segmentation and restrict access to essential only, as the CVSS 9.8 indicates trivial network exploitation.

Recommended fix High confidence

VC4 version 3.96.8 or later (for 3.x branch); 4.06.8 or later (for 4.0.x); 4.16.4 or later (for 4.1.x); 4.26.9 or later (for 4.2.x); 4.34.7 or later (for 4.3.x); 4.45.2 or later (for 4.4.x); 4.45.4 or later (for 4.5.x); 4.73.0 or later (for 4.7.x)

  1. 1. Identify the currently installed VC4 version by checking the B&R device system information or VC4 module properties.
  2. 2. Based on the installed version branch, determine the minimum fixed version to upgrade to: for 3.x.x upgrade to 3.96.8 or later; for 4.0.x upgrade to 4.06.8 or later; for 4.1.x upgrade to 4.16.4 or later; for 4.2.x upgrade to 4.26.9 or later; for 4.3.x upgrade to 4.34.7 or later; for 4.4.x upgrade to 4.45.2 or later; for 4.5.x upgrade to 4.45.4 or later; for 4.7.x upgrade to 4.73.0 or later.
  3. 3. Obtain the appropriate VC4 update package from the B&R official website (www.br-automation.com) or through your authorized B&R distribution channel.
  4. 4. Create a complete backup of the current VC4 configuration and project files before proceeding with the update.
  5. 5. Apply the VC4 update following the standard B&R software update procedure, typically via the Automation Studio or dedicated VC4 update installer.
  6. 6. After installation, verify the VC4 version has been updated to the intended fixed release.
  7. 7. Test the VNC-server authentication functionality to confirm the vulnerability has been remediated.
Caveat Review B&R release notes for specific version jumps as major version upgrades may introduce behavioral changes or require project migration steps

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

Fix this in Vc4 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2023-1617 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

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