Stack-based Buffer OverflowWeakness · CWE-121

CVE-2018-25427

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-01
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
Public exploit 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
Arm Whois 3.11 contains a stack-based buffer overflow vulnerability that allows remote attackers to execute arbitrary code by supplying oversized input to the IP address or domain field. Attackers can craft malicious input exceeding 658 bytes with shellcode to overwrite the structured exception handler and gain command execution when the application processes the input.

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

Arm Whois 3.11 contains a stack-based buffer overflow in the IP address or domain input field. Attackers can inject shellcode by sending input exceeding 658 bytes, which overwrites the structured exception handler (SEH) to achieve arbitrary code execution. This is a classic stack overflow with SEH-based exploitation.

MitigationUpdate to a patched version of Arm Whois if available; otherwise implement strict input length validation and bounds checking on all user-supplied input fields, or disable the affected service until a patch is released.

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
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 Arm Whois installation and version
    Check installed software list or locate Arm Whois executable (commonly whois.exe or armwhois.exe) and verify its version property
    Affected if Version is 3.11 or falls within the version range containing this vulnerability
  2. Determine if service is network-facing
    Check if the Whois service is listening on any network port or exposed to remote connections (common ports 43, 80, 443, or custom ports)
    Affected if Service is accessible from network or untrusted hosts
  3. Review input handling configuration
    Inspect any available configuration for Arm Whois to see if input length limits or input validation controls are defined
    Affected if No input length validation exists or limits exceed 658 bytes for domain/IP fields
  4. Check for exploitation artifacts
    Examine system logs, crash dumps, or suspicious files in the Whois service directory for evidence of buffer overflow attempts or code injection
    Affected if Any crash logs or unexpected files indicating overflow exploitation are found

If Arm Whois version 3.11 is installed and the service is network-accessible without input length restrictions under 658 bytes, the environment is affected by this vulnerability.

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

Update to a patched version of Arm Whois if available; otherwise implement strict input length validation and bounds checking on all user-supplied input fields, or disable the affected service until a patch is released.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,000
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Scan for this in your stack

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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-2018-25427 in production — separate from our analysis above.

No notes yet

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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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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