CVE-2020-8599Known exploitationNetwork attack vector

Unauthenticated arbitrary file write via directory traversal

Published Mar 18, 2020 · Updated Oct 21, 2025

Path traversal in Trend Micro Apex One 2019 and OfficeScan XG allows remote attackers to write arbitrary data anywhere on the server. A server EXE accepts a file-upload path without confining it to the intended directory, so traversal sequences redirect attacker-controlled content to an arbitrary path. No authentication is required, and a successful write bypasses ROOT login and can alter any writable server location.

CVSS severity9.8
Critical
EPSS probability11.86%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Trend Micro Apex One 2019 and OfficeScan XG allows remote attackers to write arbitrary data anywhere on the server. A server EXE accepts a file-upload path without confining it to the intended directory, so traversal sequences redirect attacker-controlled content to an arbitrary path. No authentication is required, and a successful write bypasses ROOT login and can alter any writable server location.

The record

CVE
CVE-2020-8599
Published
Mar 18, 2020
Updated
Oct 21, 2025
Vendor
Trend Micro
Product
Trend Micro Apex One
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 18, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2021Exploitation reportedCISA Known Exploited Vulnerabilities catalog listing
  3. Oct 21, 2025Record 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=OfficeScan XG (12.0), Apex One 2019 (14.0)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Trend Micro · Trend Micro Apex Oneversion=OfficeScan XG (12.0), Apex One 2019 (14.0)

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

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.

Reported exploitation

Technologies

Your stack

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Your stack

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