CVE-2013-2642 in Web Appliance
Summary
by MITRE
Sophos Web Appliance before 3.7.8.2 allows (1) remote attackers to execute arbitrary commands via shell metacharacters in the client-ip parameter to the Block page, when using the user_workstation variable in a customized template, and remote authenticated users to execute arbitrary commands via shell metacharacters in the (2) url parameter to the Diagnostic Tools functionality or (3) entries parameter to the Local Site List functionality.
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Analysis
by VulDB Data Team • 05/08/2026
The vulnerability identified as CVE-2013-2642 represents a critical command injection flaw in Sophos Web Appliance versions prior to 3.7.8.2. This security weakness stems from inadequate input validation and sanitization within multiple administrative interfaces of the web appliance. The vulnerability manifests when the appliance processes user-supplied data through customizable templates and administrative functions, creating opportunities for malicious actors to execute arbitrary commands on the underlying system. The affected components include the Block page functionality, Diagnostic Tools interface, and Local Site List management system, all of which improperly handle user input containing shell metacharacters.
The technical implementation of this vulnerability aligns with CWE-77, which describes improper neutralization of special elements used in command execution. The flaw occurs when the web appliance fails to properly sanitize input parameters before incorporating them into system commands or template variables. Specifically, when the user_workstation variable is utilized in customized templates, the appliance does not adequately filter or escape shell metacharacters present in the client-ip parameter. Similarly, the url parameter in Diagnostic Tools and entries parameter in Local Site List functionality lack proper input validation mechanisms, allowing attackers to inject malicious commands that get executed with the privileges of the web appliance service account.
The operational impact of this vulnerability is severe and multifaceted, representing a critical threat to network security infrastructure. Remote attackers can leverage this vulnerability to gain unauthorized command execution capabilities on the Sophos Web Appliance, potentially leading to complete system compromise. Authenticated users with access to diagnostic or site list management functions can also exploit this weakness, creating a broader attack surface. The consequences include unauthorized access to network traffic monitoring capabilities, potential data exfiltration, and the ability to modify or delete critical system configurations. This vulnerability essentially provides attackers with a backdoor into the organization's web filtering infrastructure, potentially allowing them to bypass security controls and access restricted network resources.
The attack surface for this vulnerability spans multiple attack vectors categorized under ATT&CK technique T1059.001 for command and scripting interpreter. The remote exploitation capability means that attackers can target the appliance from outside the network perimeter, while the authenticated path allows for more targeted attacks from within the organization. The vulnerability affects the appliance's template processing engine, diagnostic tools, and local site list management functionality, creating multiple entry points for exploitation. Organizations using affected versions of Sophos Web Appliance face significant risk of persistent threats and advanced persistent attacks that could leverage this vulnerability to establish long-term access to their network infrastructure.
Mitigation strategies for CVE-2013-2642 require immediate action to upgrade to Sophos Web Appliance version 3.7.8.2 or later, which includes proper input sanitization and validation mechanisms. Organizations should also implement network segmentation to limit access to administrative interfaces, restrict user privileges to the minimum necessary for their roles, and deploy intrusion detection systems to monitor for suspicious command execution patterns. Additionally, administrators should review and validate all customized templates to ensure they properly handle user input, and implement regular security assessments of web appliance configurations. The remediation process should include comprehensive testing of the updated appliance to ensure that security fixes do not introduce compatibility issues with existing network security policies and configurations.