dbcve.org
Apex OneApplication · Trendmicro

CVE-2020-24556

HIGH · 7.8 CVSS v3.1 Published 2020-09-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
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
A vulnerability in Trend Micro Apex One, OfficeScan XG SP1, Worry-Free Business Security 10 SP1 and Worry-Free Business Security Services on Microsoft Windows may allow an attacker to create a hard link to any file on the system, which then could be manipulated to gain a privilege escalation and code execution. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. Please note that version 1909 (OS Build 18363.719) of Microsoft Windows 10 mitigates hard links, but previous versions are affected.

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

A vulnerability in multiple Trend Micro endpoint security products (Apex One, OfficeScan XG SP1, Worry-Free Business Security 10 SP1, and Worry-Free Business Security Services) allows an attacker with low-privileged code execution to create hard links to arbitrary files on the system, enabling privilege escalation to SYSTEM-level code execution. The vulnerability stems from insufficient validation of hard link operations.

MitigationApply vendor patches for the affected Trend Micro products. For Windows 10 systems, upgrading to version 1909 (OS Build 18363.719) or later provides a built-in mitigation against hard link abuse.

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
Apex OneApplication
Affected:= 2019= saas
Worry Free Business SecurityApplication
Affected:= 10.0
Worry Free Business Security ServicesApplication
Affected:all versions

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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 installed Trend Micro products
    Open Control Panel > Programs and Features, or run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Where-Object {$_.Publisher -like "*Trend Micro*"}' to enumerate installed Trend Micro software
    Affected if No Trend Micro endpoint products are installed, then the specific vulnerability does not apply; however, if Apex One 2019, Apex One SaaS, Worry-Free Business Security 10.0, or Worry-Free Business Security Services (any version) is present, proceed to version verification
  2. Verify Apex One version
    Check the installed version of Apex One: open the Apex One console, or check registry key HKLM\SOFTWARE\TrendMicro\Apex One\CurrentVersion for the ProductVersion value
    Affected if Version equals 2019 or is the SaaS variant indicates the environment falls within the affected version range
  3. Verify Worry-Free Business Security version
    Check the installed version: open the WFBS console, or locate the installed version in Programs and Features, or check registry under HKLM\SOFTWARE\TrendMicro\Worry-Free Business Security\CurrentVersion
    Affected if Version 10.0 (specifically 10.0 SP1) indicates the environment is within the affected version range
  4. Verify Worry-Free Business Security Services
    Check if the SaaS-hosted Worry-Free Business Security Services agent is deployed: check for the Trend Micro SaaS endpoint protection agent installation or check the console for tenant status
    Affected if Any active Worry-Free Business Security Services deployment means the environment is affected since all versions are in scope
  5. Confirm vulnerable component presence
    Verify the Trend Micro Security Agent (OSCE agent) is running: check Services.msc for 'Trend Micro Security Agent' service, or check process list for 'TMCCSF.exe' or 'PccNTMon.exe' processes
    Affected if The Security Agent service is installed and running, indicating the component with the hard link validation flaw is present

Your environment is affected if you have Apex One 2019, Apex One SaaS, Worry-Free Business Security 10.0 (SP1), or any version of Worry-Free Business Security Services installed with the corresponding Security Agent component active.

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 vendor patches for the affected Trend Micro products. For Windows 10 systems, upgrading to version 1909 (OS Build 18363.719) or later provides a built-in mitigation against hard link abuse.

Fix this in Apex One Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,880
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,808.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-24556 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2020-24556 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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
  • No spam, self-promotion, credentials, or personal data