Improper Certificate ValidationWeakness · CWE-295

CVE-2025-42611

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
74/100
Remediation priority · Elevated
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
RouterOS provides various services that rely on correct verification of client and server certificates to secure confidentiality and integrity of communications. This includes OpenVPN, CAPsMAN, Dot1x (802.1X), among others. The vulnerability lies in shared certificate validation logic which uses the system certificate store that is shared and equally trusted by all system services. This causes confusion of scope, allowing any certificate authority present in the system-wide trust store to be trusted in any context (with some exceptions), allowing partial or full authentication bypass in CAPsMAN, OpenVPN, Dot1X and potentially others.

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

RouterOS has a scope confusion vulnerability in its shared certificate validation logic. The system-wide certificate store is used uniformly across multiple services (OpenVPN, CAPsMAN, Dot1X), allowing any CA present in the shared trust store to be trusted regardless of the service context. This enables authentication bypass by leveraging CAs that should only be valid for specific services.

MitigationSeparate certificate trust stores per service to ensure each service (OpenVPN, CAPsMAN, Dot1X) only trusts the CAs intended for its specific context, preventing cross-service trust abuse.

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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. List all certificates in RouterOS
    Run `/certificate print` in RouterOS terminal to display all certificates in the system certificate store
    Affected if Multiple CA certificates exist in the store, especially where some are intended for specific services only
  2. Check running services using certificates
    Run `/ip service print` and `/interface bridge print` (for CAPsMAN) to identify if OpenVPN, CAPsMAN, or Dot1X services are active and configured
    Affected if Any of these services are enabled and configured to use certificate authentication
  3. Verify OpenVPN certificate configuration
    Run `/interface ovpn-server server print` to check if `auth` and `cipher` settings include certificate-based authentication
    Affected if OpenVPN server is enabled with certificate authentication and multiple CAs exist in the store
  4. Verify CAPsMAN certificate configuration
    Run `/caps-man manager print` and `/caps-man configuration print` to check if CAPsMAN is configured with certificate-based access control
    Affected if CAPsMAN is enabled with certificate authentication and multiple CAs exist in the store
  5. Verify Dot1X certificate configuration
    Run `/interface bridge port` and check for Dot1X settings via `/interface dot1x` to see if certificate authentication is configured on bridge ports
    Affected if Dot1X is configured with certificate authentication and multiple CAs exist in the store

You are affected if your RouterOS system has multiple CA certificates in its shared certificate store while any of OpenVPN, CAPsMAN, or Dot1X services are configured to use certificate authentication, because CAs intended for one service can be abused to authenticate to another.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Separate certificate trust stores per service to ensure each service (OpenVPN, CAPsMAN, Dot1X) only trusts the CAs intended for its specific context, preventing cross-service trust abuse.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing12.0 h
  • Review / QA6.0 h
50.0 hours of engineering $8,800
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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-2025-42611 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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