CVE-2021-42104

SYSTEM code execution via pipe client impersonation

Published Oct 21, 2021 · Updated Aug 4, 2024

Local privilege escalation in Trend Micro Apex One and Worry-Free Business Security allows local users to execute code as SYSTEM. The Security Agent lets an untrusted process impersonate a pipe client, adopting the privileged client's security context. Exploitation requires low-privileged code execution on a Windows host; affected releases include Apex One 2019 or SaaS and WFBS 10.0 SP1 or Services.

CVSS severity7.8
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in Trend Micro Apex One and Worry-Free Business Security allows local users to execute code as SYSTEM. The Security Agent lets an untrusted process impersonate a pipe client, adopting the privileged client's security context. Exploitation requires low-privileged code execution on a Windows host; affected releases include Apex One 2019 or SaaS and WFBS 10.0 SP1 or Services.

The record

CVE
CVE-2021-42104
Published
Oct 21, 2021
Updated
Aug 4, 2024
Vendor
Trend Micro
Product
Trend Micro Worry-Free Business Security
Classifications
CWE-269, T1134.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0 SP1, Services (SaaS)

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Trend Micro · Trend Micro Worry-Free Business Securityversion=10.0 SP1, Services (SaaS)
Trend Micro · Trend Micro Apex Oneversion=2019, SaaS

Published CVSS scores

7.0Trend Micro Zero Day InitiativeCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Trend MicroCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1134.001Token Impersonation/Theft

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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