CVE-2017-6183 in Web Appliance
Summary
by MITRE
In Sophos Web Appliance (SWA) before 4.3.1.2, a section of the machine's configuration utilities for adding (and detecting) Active Directory servers was vulnerable to remote command injection, aka NSWA-1314.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 08/24/2020
The vulnerability identified as CVE-2017-6183 affects Sophos Web Appliance versions prior to 4.3.1.2 and represents a critical remote command injection flaw within the Active Directory server configuration utilities. This vulnerability resides in the section responsible for adding and detecting Active Directory servers, making it particularly dangerous as it allows unauthorized remote attackers to execute arbitrary commands on the affected system. The flaw specifically impacts the configuration management functionality of the web appliance, which serves as a central security gateway for organizations. The vulnerability is classified as a command injection issue, which falls under CWE-77 and aligns with ATT&CK technique T1059.001 for command and script injection, demonstrating how attackers can leverage this weakness to gain full system control.
The technical implementation of this vulnerability stems from insufficient input validation and sanitization within the Active Directory server detection and addition processes. When administrators or automated systems interact with the SWA configuration utilities to add or detect Active Directory servers, the appliance fails to properly sanitize user-supplied input parameters. This lack of input validation creates an exploitable condition where maliciously crafted input can be interpreted and executed as shell commands by the underlying operating system. The vulnerability exists in the appliance's web interface configuration utilities, where user-provided data is directly incorporated into system commands without proper escaping or filtering mechanisms. Attackers can exploit this by injecting command separators or shell metacharacters into the Active Directory server configuration fields, thereby gaining unauthorized access to the system's command execution layer.
The operational impact of CVE-2017-6183 is severe and far-reaching for organizations relying on Sophos Web Appliance for their security infrastructure. Successful exploitation allows attackers to execute arbitrary commands with the privileges of the web appliance service account, potentially leading to complete system compromise. This vulnerability enables attackers to perform reconnaissance activities, install backdoors, modify security policies, and access sensitive network resources that the appliance is designed to protect. The attack surface is particularly concerning because Active Directory integration is fundamental to enterprise security infrastructure, making this vulnerability a prime target for attackers seeking persistent access to corporate networks. Organizations using affected SWA versions face risks of data breaches, privilege escalation, and potential lateral movement within their network environments, as the compromised appliance could serve as a foothold for broader attacks. The vulnerability's remote nature means that attackers do not require physical access or network credentials to exploit it, making it particularly dangerous in environments where network segmentation is not properly implemented.
Organizations should immediately implement mitigation strategies including patching to Sophos Web Appliance version 4.3.1.2 or later, which contains the necessary fixes for this vulnerability. Network segmentation should be implemented to isolate the web appliance from critical systems, and access controls should be tightened to limit who can interact with the appliance's configuration utilities. Regular monitoring of system logs for suspicious command execution patterns is essential, as is implementing intrusion detection systems that can identify exploitation attempts. Security teams should conduct thorough vulnerability assessments to ensure no other similar flaws exist within the appliance's configuration utilities, and implement proper input validation controls across all user-facing interfaces. Additionally, organizations should consider disabling unnecessary Active Directory integration features when not required and maintain up-to-date security baselines for all network security appliances to prevent similar vulnerabilities from being exploited in the future. The vulnerability demonstrates the critical importance of input validation in web applications and the severe consequences that can result from inadequate sanitization of user-provided data in security infrastructure devices.