CVE-2016-10257 in Advanced Secure Gateway
Summary
by MITRE
The Symantec Advanced Secure Gateway (ASG) 6.6, ASG 6.7 (prior to 6.7.2.1), ProxySG 6.5 (prior to 6.5.10.6), ProxySG 6.6, and ProxySG 6.7 (prior to 6.7.2.1) management console is susceptible to a reflected XSS vulnerability. A remote attacker can use a crafted management console URL in a phishing attack to inject arbitrary JavaScript code into the management console web client application. This is a separate vulnerability from CVE-2016-10256.
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Analysis
by VulDB Data Team • 01/29/2021
The Symantec Advanced Secure Gateway and ProxySG products represent critical components in enterprise network security infrastructure, providing web filtering, content inspection, and secure gateway functionalities for organizations worldwide. These appliances serve as central management points for security policies and configurations, making their management consoles prime targets for attackers seeking to compromise enterprise security postures. The vulnerability affects multiple versions including ASG 6.6, ASG 6.7 (prior to 6.7.2.1), ProxySG 6.5 (prior to 6.5.10.6), ProxySG 6.6, and ProxySG 6.7 (prior to 6.7.2.1), indicating a widespread exposure across the product lineage. This reflected cross-site scripting vulnerability specifically targets the management console web interface, which serves as the primary administrative access point for configuring and monitoring security policies.
The technical flaw manifests in the improper handling of user-supplied input within the management console URL parameters. When an attacker crafts a malicious URL containing JavaScript code and delivers it to an authenticated user through phishing campaigns, the vulnerable application reflects this malicious content back to the user's browser without proper sanitization or encoding. This creates a classic reflected XSS scenario where the attacker's payload executes within the victim's browser context, leveraging the user's existing authentication session to the management console. The vulnerability operates at the web application layer and specifically affects the HTTP response handling mechanism, where input validation fails to properly escape or filter user-provided parameters before rendering them in the web page output. According to CWE-79, this represents a classic cross-site scripting weakness where the application incorporates untrusted data into web pages without proper validation or encoding, making it susceptible to malicious script injection.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with a potential entry point for more sophisticated attacks within the compromised environment. An attacker who successfully exploits this vulnerability could potentially escalate privileges, modify security policies, access sensitive configuration data, or redirect users to malicious sites. The management console represents a high-value target since it contains administrative credentials, security policy configurations, and potentially sensitive network information. The reflected nature of the vulnerability means that attackers do not need persistent access or complex exploitation techniques, as the attack can be delivered through simple phishing emails or malicious links. This vulnerability directly maps to ATT&CK technique T1059.007 for command and scripting interpreter, and T1566 for phishing attacks, demonstrating how this vulnerability can serve as a gateway for broader compromise activities.
Organizations should prioritize immediate patching of affected systems, with the most critical remediation being the upgrade to versions 6.7.2.1 for ASG and ProxySG 6.5.10.6 for ProxySG 6.5. The vulnerability's exposure through phishing campaigns makes proactive security awareness training essential for administrators, as social engineering remains a primary attack vector. Network segmentation and access controls should be implemented to limit management console exposure, while monitoring for suspicious URL patterns and user behavior can help detect potential exploitation attempts. Security teams should also consider implementing web application firewalls to detect and block malicious URL patterns targeting this specific vulnerability. The incident highlights the importance of regular security assessments and vulnerability management processes, particularly for critical infrastructure components that serve as administrative interfaces for enterprise security systems.