CVE-2017-13677 in Advanced Secure Gateway
Summary
by MITRE
Denial-of-service (DoS) vulnerability in the Symantec Advanced Secure Gateway (ASG) and ProxySG management consoles. A remote attacker can use crafted HTTP/HTTPS requests to cause denial-of-service through management console application crashes.
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Analysis
by VulDB Data Team • 02/09/2021
The CVE-2017-13677 vulnerability represents a critical denial-of-service weakness affecting Symantec Advanced Secure Gateway (ASG) and ProxySG management consoles. This flaw resides within the web-based management interfaces of these security appliances, making it particularly dangerous as it can be exploited remotely without requiring authentication. The vulnerability stems from inadequate input validation mechanisms within the HTTP/HTTPS request processing components of the management console applications. Attackers can craft specifically formatted requests that, when processed by the vulnerable systems, trigger application crashes and subsequent service disruptions. The affected systems include various versions of Symantec's ASG and ProxySG appliances, which are widely deployed in enterprise environments for web filtering, content control, and security policy enforcement.
The technical implementation of this vulnerability involves improper handling of malformed HTTP requests within the management console's web server component. When the system receives crafted requests containing maliciously constructed headers or payload data, the processing logic fails to properly sanitize or validate the input before attempting to parse or execute the request. This leads to memory corruption conditions or unexpected execution paths that cause the management console application to terminate abruptly. The vulnerability is classified as a buffer overflow or input validation flaw under the Common Weakness Enumeration framework, specifically aligning with CWE-121 for buffer overflow conditions. The attack surface is particularly concerning as the management console typically operates on well-known ports and is accessible over the network, making it an attractive target for remote exploitation.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network security infrastructures. Organizations relying on Symantec ASG and ProxySG appliances for their web security operations face significant risk when this vulnerability is exploited, as the management console crashes can render the entire appliance inaccessible for configuration changes, policy updates, or monitoring activities. During an active attack, administrators lose the ability to manage security policies, view logs, or respond to security incidents in real-time, creating windows of exposure for malicious actors. The DoS condition affects not only the management interface but can also potentially impact the appliance's ability to process normal traffic, depending on the specific implementation and system architecture. This vulnerability directly maps to the ATT&CK technique T1499.004 for Network Denial of Service, where adversaries leverage system weaknesses to disrupt network services.
Mitigation strategies for CVE-2017-13677 should include immediate implementation of Symantec's official security patches and updates, which address the input validation flaws in the management console components. Organizations should also implement network segmentation to limit access to the management console interfaces, ensuring that only authorized administrative systems can reach these ports. Additional protective measures include deploying network monitoring solutions to detect anomalous HTTP request patterns that may indicate exploitation attempts, implementing strict access controls and authentication mechanisms, and establishing redundant management access methods to maintain operational continuity. Security teams should also consider disabling unnecessary management services when not actively required, and regularly review and audit access logs for suspicious activities. The vulnerability underscores the importance of maintaining current security patches and implementing defense-in-depth strategies to protect critical infrastructure components from remote exploitation attempts.