CVE-2021-28645
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 · uneditedAn incorrect permission assignment vulnerability in Trend Micro Apex One, Apex One as a Service and OfficeScan XG SP1 could allow a local attacker to escalate privileges on affected installations. Please note: an attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
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 confidenceThis is a local privilege escalation vulnerability in Trend Micro endpoint security products (Apex One, Apex One as a Service, and OfficeScan XG SP1) stemming from incorrect permission assignments. An attacker who has already achieved low-privileged code execution on the target system can exploit improper permission settings to elevate to SYSTEM or administrative privileges.
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= 2019= xgCVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify installed Trend Micro productCheck for presence of Apex One or OfficeScan XG by examining Program Files for Trend Micro directories, or check Windows Services for Trend Micro-related servicesAffected if Apex One 2019 or OfficeScan XG is installed
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Determine installed versionCheck the product version through Windows Registry at HKLM\SOFTWARE\TrendMicro\Apex One or OSCE\, or use the product's built-in about/version information in the management consoleAffected if Version matches 2019 for Apex One or XG for OfficeScan
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Verify service accountsInspect the Log On As account for Trend Micro services (such as Apex One, TmListen, or OfficeScan services) in Windows Services propertiesAffected if Services run under SYSTEM or administrator-level accounts (which is default for vulnerable configurations)
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Check file permissions on Trend Micro directoriesUse icacls or PowerShell Get-Acl on the main Trend Micro installation directory (typically C:\Program Files\Trend Micro\) to inspect permission inheritanceAffected if Low-privileged users can modify executable files or configuration files in the installation folder
A user is affected if they have Apex One 2019 or OfficeScan XG installed with default permissions, allowing a low-privileged user with code execution to escalate to SYSTEM privileges through improperly secured files or configurations.
Generated from the published advisory. Verify against your own configuration.
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 dataApply the vendor security patch when available. In the interim, limit local user privileges and restrict code execution capabilities to reduce the attack surface for initial access.
- Consultation2.0 h
- Implementation3.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,040.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-28645 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-28645 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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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