---
id: "CVE-2020-8599"
kind: "vulnerability"
aliases: ["CVE-2020-8599"]
title: "Trend Micro Apex One and OfficeScan: Trend Micro Apex One and OfficeScan Authentication Bypass Vulnerability"
severity: "critical"
cvss: 10.0
epss: 0.11858
exploited: true
status: "open"
category: "vendor"
products: [{"name": "Trend Micro Apex One and OfficeScan", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["apex-one", "exploited", "officescan", "self-hosted", "vendor", "windows"]
not_affected_if: ["managed-hosting", "patched-server"]
published_at: "2020-03-18T01:15:12+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T20:29:29+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-8599", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2020-8599", "first_seen_at": "2026-10-23T19:13:43+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-8599", "first_seen_at": "2026-10-23T19:35:23+00:00"}]
---

# Trend Micro Apex One and OfficeScan: Trend Micro Apex One and OfficeScan Authentication Bypass Vulnerability

Trend Micro Apex One (2019) and OfficeScan XG server contain a vulnerable EXE that lets a remote, unauthenticated attacker write arbitrary data to arbitrary paths and bypass ROOT login. Attackers can take over the security server and the endpoints it manages.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Trend Micro Apex One and OfficeScan affected ? fixed ?

## How to check

Check the installed Apex One or OfficeScan server version against Trend Micro's advisory; the sources do not give a file or setting to inspect.

## Fix

Apply the Trend Micro patch or hotfix for Apex One and OfficeScan referenced in the advisory; the sources do not name the fixed version.
Restrict access to the management console to trusted networks until patched.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-8599
- 2026-10-23T19:13:43+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2020-8599
- 2026-10-23T19:35:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2020-8599

## From the sources

Trend Micro Apex One (2019) and OfficeScan XG server contain a vulnerable EXE file that could allow a remote attacker to write arbitrary data to an arbitrary path on affected installations and bypass ROOT login. Authentication is not required to exploit this vulnerability.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_