ViosApplication · Ibm

CVE-2025-36251

CRITICAL · 9.8 CVSS v3.1 Published 2025-11-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
IBM AIX 7.2, and 7.3 and IBM VIOS 3.1, and 4.1 nimsh service SSL/TLS implementations could allow a remote attacker to execute arbitrary commands due to improper process controls. This addresses additional attack vectors for a vulnerability that was previously addressed in CVE-2024-56347.

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

The nimsh (NIM shell) service on IBM AIX 7.2/7.3 and VIOS 3.1/4.1 contains improper process controls in its SSL/TLS implementation, allowing remote attackers to execute arbitrary commands. This is a follow-up to CVE-2024-56347 addressing additional attack vectors.

MitigationApply IBM's security patches for this vulnerability to all affected AIX and VIOS systems. Restrict network access to the nimsh service and disable it if not required.

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
ViosApplication
Affected:= 3.1.0= 4.1.0
AixOperating system
Affected:= 7.2= 7.3

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. Identify the installed AIX or VIOS version
    Run 'oslevel -s' on AIX or 'ioslevel' on VIOS to obtain the exact version number
    Affected if The version matches 7.2, 7.3, 3.1.0, or 4.1.0 exactly
  2. Determine if nimsh service is enabled
    Run 'lssrc -s nimsh' or check '/etc/inittab' for nimsh entries to see if the NIM shell service is configured
    Affected if The nimsh service is listed as active or the nimsh entry exists in inittab
  3. Check nimsh SSL/TLS configuration
    Examine the nimsh configuration in '/etc/nimsh' or run 'lsattr -El nimsh0' to see if SSL or TLS options are enabled
    Affected if SSL or TLS is enabled for the nimsh service (such as 'ssl' or 'secure' attributes set to 'true')
  4. Verify if security patches are applied
    Run 'instfix -i' with appropriate APAR numbers for this CVE, or use 'emgr -l' on VIOS to list installed fixes
    Affected if No patches for CVE-2025-36251 are installed or the APAR is not listed as applied

A system is affected if it runs AIX 7.2/7.3 or VIOS 3.1.0/4.1.0 with the nimsh service enabled and SSL/TLS configured, and lacks the relevant security patches.

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

Apply IBM's security patches for this vulnerability to all affected AIX and VIOS systems. Restrict network access to the nimsh service and disable it if not required.

Fix this in Vios Scoped from the published advisory
  • Consultation12.0 h
  • Implementation20.0 h
  • Testing12.0 h
  • Review / QA6.0 h
50.0 hours of engineering $8,880
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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-2025-36251 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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