CVE-2021-28646

Log-file takeover via insecure file permissions

Published Apr 13, 2021 · Updated Aug 3, 2024

Insecure file permissions in Trend Micro Apex One 2019/SaaS and OfficeScan XG SP1 allow local users to control a product log file. The products maintain an otherwise unspecified log file with permissions that let low-privileged code replace or modify it. Execution of low-privileged code or equivalent local access is required, and the documented consequence is limited to loss of integrity for that log file.

CVSS severity5.5
Medium
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure file permissions in Trend Micro Apex One 2019/SaaS and OfficeScan XG SP1 allow local users to control a product log file. The products maintain an otherwise unspecified log file with permissions that let low-privileged code replace or modify it. Execution of low-privileged code or equivalent local access is required, and the documented consequence is limited to loss of integrity for that log file.

The record

CVE
CVE-2021-28646
Published
Apr 13, 2021
Updated
Aug 3, 2024
Vendor
Trend Micro
Product
Trend Micro Apex One
Classifications
CWE-732, T1565.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=2019, SaaS

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Trend Micro · Trend Micro Apex Oneversion=2019, SaaS
Trend Micro · Trend Micro OfficeScanversion=XG SP1

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
4.7Trend MicroCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

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-732Incorrect Permission Assignment for Critical Resource
T1565.001Stored Data Manipulation

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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