dbcve.org
Improper Certificate ValidationWeakness · CWE-295

CVE-2025-11043

HIGH · 7.4 CVSS v3.1 Published 2026-01-19
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
83/100
Remediation priority · High
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
An Improper Certificate Validation vulnerability in the OPC-UA client and ANSL over TLS client used in Automation Studio versions before 6.5 could allow an unauthenticated attacker on the network to position themselves to intercept and interfere with data exchanges.

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 · moderate confidence

This is an improper certificate validation vulnerability in the OPC-UA client and ANSL over TLS client components of B&R Automation's Automation Studio. The flaw allows an unauthenticated network attacker to perform man-in-the-middle (MITM) attacks by intercepting TLS connections, potentially due to missing or insufficient validation of server certificates (e.g., not verifying certificate chain, hostname, or validity). This enables eavesdropping and tampering with industrial process data.

MitigationUpgrade Automation Studio to version 6.5 or later, which contains proper certificate validation logic. If immediate patching is not possible, restrict network access to industrial assets and ensure TLS endpoints use certificates from trusted CAs with proper hostname validation.

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

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

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

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. Identify installed Automation Studio version
    Locate Automation Studio in the installed programs list or check the program directory for version information. Common locations: C:\Program Files\B&R Automation\Studio\ or check Windows Programs and Features.
    Affected if The installed version is earlier than 6.5 (e.g., 6.4.x, 6.3.x, or earlier)
  2. Determine if OPC-UA client is in use
    Review Automation Studio project configurations for OPC-UA client connections. Check project files, network configuration settings, or runtime logs for references to OPC-UA client communication.
    Affected if OPC-UA client connections are configured and enabled in the project or runtime environment
  3. Determine if ANSL over TLS client is in use
    Review project settings for ANSL (Automation Studio Network Library) communications. Check if TLS encryption is enabled for ANSL connections in the network or communication configuration panels.
    Affected if ANSL over TLS client connections are configured and enabled
  4. Check if TLS is actively used for industrial communications
    Inspect the communication configuration for OPC-UA or ANSL endpoints. Verify that security policies are set to use TLS/SSL (such as Basic128rsa15, Basic256, or higher) rather than None or plaintext.
    Affected if TLS is enabled for OPC-UA or ANSL client communications (the vulnerability applies specifically to TLS connections with improper validation)

A user is affected if they have Automation Studio versions older than 6.5 with OPC-UA or ANSL over TLS client features enabled and communicating with servers over TLS.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Automation Studio to version 6.5 or later, which contains proper certificate validation logic. If immediate patching is not possible, restrict network access to industrial assets and ensure TLS endpoints use certificates from trusted CAs with proper hostname validation.

Recommended fix Moderate confidence

Automation Studio 6.5 or later

  1. Verify current Automation Studio version by opening the IDE and checking the 'Help > About' or 'Info' section
  2. Backup all current projects, libraries, and configurations before upgrading
  3. Download Automation Studio version 6.5 or later from the B&R Automation website (www.br-automation.com) or your authorized distributor
  4. Run the installer with administrative privileges
  5. Follow the on-screen upgrade wizard prompts, selecting 'Upgrade' to preserve existing settings
  6. After installation, verify the new version in 'Help > About'
  7. Test that OPC-UA and ANSL over TLS connections function correctly with proper certificate validation
Caveat Review release notes for potential project or library compatibility changes; older runtime versions may require corresponding updates

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

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
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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-2025-11043 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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