Trend Micro OfficeScan Directory Traversal Remote Code Execution Vulnerability (CVE-2019-18187) Security Advisory
Executive & SecOps Summary
SECOPS ASSESSMENTTrend Micro OfficeScan versions 11.0 and XG (12.0)
An attacker can exploit a directory traversal vulnerability to extract arbitrary files from a malicious ZIP archive into the web root, potentially leading to Remote Code Execution (RCE)
Apply the official critical patches immediately and restrict access to the OfficeScan management console
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Official Patch & Version Upgrade Commands
Administrators must immediately apply the latest Critical Patch or Service Pack provided by Trend Micro.
# Verify the current OfficeScan version and patch level via Registry (PowerShell)
$RegistryPath = 'HKLM:\SOFTWARE\Wow6432Node\TrendMicro\OfficeScan\service\Information'
Get-ItemProperty -Path $RegistryPath -Name 'Version', 'ServicePack', 'Patch' -ErrorAction SilentlyContinue2. Temporary Workaround & Hardening Configuration
Before applying the patch, restrict access to the OfficeScan management console (default ports 4343, 8080) using firewall rules or IIS IP Address and Domain Restrictions.
<!-- Example IIS web.config snippet to restrict access to trusted IP ranges only -->
<configuration>
<system.webServer>
<security>
<ipSecurity allowUnlisted='false'>
<clear />
<!-- Allow trusted administrator subnet -->
<add ipAddress='10.0.0.0' subnetMask='255.255.255.0' allowed='true' />
</ipSecurity>
</security>
</system.webServer>
</configuration>3. Log Audit & IoC Verification Commands
Inspect the OfficeScan web console directories for newly created or unauthorized executable files, and review web server access logs for suspicious ZIP upload activities.
# Scan the OfficeScan web console directory for recently modified or created ASPX files
$WebConsolePath = 'C:\Program Files (x86)\Trend Micro\OfficeScan\PCCSRV\Admin\'
Get-ChildItem -Path $WebConsolePath -Filter *.aspx -Recurse | Where-Object { $_.LastWriteTime -gt (Get-Date).AddDays(-30) } | Select-Object FullName, Length, LastWriteTimeBlock Exploits Instantly with Managed Virtual Patching Rules
Can't patch production immediately? Deploy managed WAF rules at the edge to intercept RCE, SQLi, and deserialization payloads before they hit your origin server.
Technical Root Cause & Exploitation Mechanics
1. Vulnerability Overview & Root Cause
This vulnerability (CVE-2019-18187) is a directory traversal flaw (CWE-22) residing in the file upload and extraction mechanism of the Trend Micro OfficeScan server. The root cause is the server's failure to properly sanitize and validate file paths contained within user-supplied ZIP archives before extraction. This allows an attacker to craft a ZIP archive containing relative path traversal sequences (e.g., '../../') to write arbitrary files outside of the intended directory.
2. Exploitation Mechanics & Attack Scenario
An attacker constructs a malicious ZIP archive containing an executable script (such as an ASPX web shell) with its internal file path manipulated to include directory traversal sequences (e.g., ../../../../inetpub/wwwroot/officescan/console/html/shell.aspx). When this ZIP file is uploaded to a vulnerable endpoint on the OfficeScan server, the extraction process writes the web shell directly into a web-accessible directory. The attacker then accesses the uploaded web shell via HTTP/HTTPS to execute arbitrary system commands under the security context of the web service account.
3. Infrastructure & Business Impact
This vulnerability is actively exploited in the wild and is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Successful exploitation grants the attacker control over the OfficeScan management server, which orchestrates endpoint security across the enterprise. Although the execution privilege is bound to the web service account, attackers can leverage local privilege escalation (LPE) techniques to gain full administrative control, disable endpoint protection, and pivot deeper into the internal network.
Official Vendor Advisories & References
Trend Micro OfficeScan versions 11.0 and XG (12.0) could be exploited by an attacker utilizing a directory traversal vulnerability to extract files from an arbitrary zip file to a specific folder on the OfficeScan server, which could potentially lead to remote code execution (RCE). The remote process execution is bound to a web service account, which depending on the web platform used may have restricted permissions. An attempted attack requires user authentication.
Frequently Asked SecOps Questions (CVE-2019-18187)
FAQQ1. How critical is CVE-2019-18187 and is it actively exploited in the wild?
CVE-2019-18187 is rated CVSS 7.5 (HIGH) with a 30-day EPSS exploitation probability of 25.1%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.
Q2. Which vendors and products are affected by CVE-2019-18187?
Primary impacted vendors include trendmicro across officescan. Scope summary: Trend Micro OfficeScan versions 11.0 and XG (12.0)
Q3. What temporary mitigations or workarounds exist for CVE-2019-18187 before patching?
[Mitigation] Apply the official critical patches immediately and restrict access to the OfficeScan management console Follow the CLI remediation commands and interactive SecOps checklist on this page to restrict exposure prior to your maintenance window.
Generate an Internal Engineering Notice or CISO Report for CVE-2019-18187
Instantly format this advisory into an executive CISO summary or engineering patch ticket.
🔗 Related Advisories in Similar Stack (trendmicro)
View Category →Trend Micro Apex One On-Premise Directory Traversal and Remote Code Execution Vulnerability (CVE-2026-34926)
[Affected Scope] Trend Micro Apex One (On-Premise) server installations.
Adobe ColdFusion Path Traversal Remote Code Execution Vulnerability Urgent Advisory (CVE-2026-48282)
[Affected Scope] Adobe ColdFusion versions 2025.9, 2023.20 and earlier
WebDyne Perl Framework Path Traversal and Remote Code Execution (RCE) Vulnerability Advisory (CVE-2026-78189)
[Affected Scope] Perl web applications utilizing WebDyne versions 3.007 through 3.021
Ahsay AhsayCBS Replication Receiver Remote Code Execution (RCE) Vulnerability Advisory (CVE-2026-105134)
[Affected Scope] AhsayCBS versions up to 9.15.2.69 and 10.3.4.44, specifically the Replication Receiver component
Subscribe to Daily Vulnerability Briefings & KEV Alerts
Concise morning briefings for SecOps, DevSecOps, and SRE teams covering newly exploited CVEs and mitigation priorities.