CVE-2017-11392 in InterScan Messaging Virtual Appliance
Summary
by MITRE
Proxy command injection vulnerability in Trend Micro InterScan Messaging Virtual Appliance 9.0 and 9.1 allows remote attackers to execute arbitrary code on vulnerable installations. The specific flaw can be exploited by parsing the "T" parameter within modTMCSS Proxy. Formerly ZDI-CAN-4745.
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Analysis
by VulDB Data Team • 11/03/2019
The vulnerability identified as CVE-2017-11392 represents a critical proxy command injection flaw affecting Trend Micro InterScan Messaging Virtual Appliance versions 9.0 and 9.1. This security weakness resides within the modTMCSS Proxy component where the system fails to properly sanitize user input when processing the "T" parameter. The flaw enables remote attackers to inject malicious commands that can be executed within the context of the vulnerable appliance, potentially leading to complete system compromise and unauthorized access to sensitive email communications. The vulnerability was previously catalogued as ZDI-CAN-4745, highlighting its significance in the cybersecurity community. This issue falls under the CWE-94 category of Code Injection, specifically representing a command injection vulnerability that allows attackers to execute arbitrary system commands through improperly validated input.
The technical exploitation of this vulnerability occurs when an attacker sends a crafted request containing malicious input within the "T" parameter of the modTMCSS Proxy module. The appliance processes this parameter without adequate validation or sanitization, allowing the injected commands to be interpreted and executed by the underlying operating system. This type of vulnerability represents a classic command injection attack vector where the attacker can leverage the proxy functionality to execute arbitrary code on the target system. The impact is particularly severe because the InterScan Messaging Virtual Appliance serves as a critical email security component, making successful exploitation potentially devastating for organizations relying on its protection. The vulnerability demonstrates poor input validation practices and highlights the importance of proper sanitization of all user-supplied data in web applications and proxy systems.
From an operational perspective, the implications of this vulnerability extend far beyond simple code execution. Attackers who successfully exploit this flaw can gain full control over the messaging appliance, potentially allowing them to intercept, modify, or delete email communications passing through the system. The compromised appliance could serve as a pivot point for attacking internal network resources, as it typically operates within the email infrastructure of organizations. The vulnerability affects organizations using Trend Micro InterScan Messaging Virtual Appliance versions 9.0 and 9.1, which represent a significant portion of enterprise email security deployments. Security professionals should note that the attack surface is particularly broad since the vulnerability allows remote exploitation without requiring authentication, making it highly attractive to threat actors. This vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, where adversaries leverage system command execution capabilities to achieve their objectives.
Organizations affected by CVE-2017-11392 should implement immediate mitigations including applying the vendor-provided patches and updates released by Trend Micro to address the command injection vulnerability. Network segmentation should be implemented to limit access to the affected appliance, and monitoring should be enhanced to detect suspicious proxy requests containing unusual parameter values. The remediation process should include thorough validation of all input parameters within the modTMCSS Proxy module to prevent similar vulnerabilities from emerging in the future. Security teams should conduct comprehensive vulnerability assessments of their email infrastructure to identify other potential command injection points and ensure proper input validation throughout all components. Additionally, implementing web application firewalls and intrusion detection systems can provide additional layers of protection against exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper input validation and output encoding in preventing command injection attacks, particularly in security appliances that handle sensitive communications data.