CVE-2019-16100 in EdgeConnect SD-WAN
Summary
by MITRE
Silver Peak EdgeConnect SD-WAN before 8.1.7.x allows remote attackers to trigger a web-interface outage via slow client-side HTTP traffic from a single source.
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Analysis
by VulDB Data Team • 12/18/2023
The vulnerability identified as CVE-2019-16100 affects Silver Peak EdgeConnect SD-WAN appliances running versions prior to 8.1.7.x, presenting a significant security risk that enables remote attackers to disrupt web interface availability through carefully crafted slow HTTP client traffic patterns. This issue represents a classic example of a resource exhaustion attack that targets the web server component of the SD-WAN appliance, potentially leading to complete service disruption for administrators and legitimate users attempting to access the management interface.
The technical flaw stems from insufficient input validation and rate limiting mechanisms within the web interface's HTTP request processing capabilities. When a single attacker establishes multiple slow HTTP connections or sends HTTP requests at a deliberately slow pace, the appliance's web server becomes overwhelmed with pending connections that consume system resources without being properly terminated or managed. This behavior creates a denial of service condition where legitimate administrative sessions cannot be established due to resource exhaustion, effectively rendering the web interface unavailable to authorized users who need to manage the SD-WAN infrastructure.
From an operational impact perspective, this vulnerability poses a critical threat to network management and monitoring capabilities within enterprise environments that rely on Silver Peak EdgeConnect appliances for software-defined wide area networking. The disruption of the web interface means that network administrators lose their primary means of configuring, monitoring, and troubleshooting the SD-WAN infrastructure, potentially leading to extended service outages and operational inefficiencies. The attack can be executed remotely without requiring authentication credentials, making it particularly dangerous as any attacker with network access can exploit this weakness to cause service disruption.
The vulnerability aligns with CWE-400, which categorizes resource exhaustion issues, and demonstrates characteristics consistent with attack patterns documented in the MITRE ATT&CK framework under the T1499 category for network denial of service attacks. Organizations utilizing affected EdgeConnect appliances face significant risk of operational disruption, particularly in mission-critical environments where SD-WAN management interfaces must remain available for continuous network operations. The slow HTTP traffic pattern used in this attack is designed to avoid detection by traditional network monitoring tools that might not immediately recognize the benign nature of slow connections as a potential threat vector.
Security practitioners should implement immediate mitigations including applying the vendor-provided patch to upgrade to Silver Peak EdgeConnect version 8.1.7.x or later, which contains the necessary fixes for this vulnerability. Network administrators should also consider implementing rate limiting and connection tracking mechanisms at the network perimeter to detect and prevent slow HTTP traffic patterns that could indicate exploitation attempts. Additionally, organizations should ensure that administrative access to the SD-WAN appliances is restricted to trusted networks and that multiple access methods are available to maintain operational continuity in case of interface disruption. The vulnerability highlights the importance of proper resource management and input validation in web server implementations, particularly for network infrastructure devices that must maintain availability under various attack conditions.