CVE-2015-3810 in Wireshark
Summary
by MITRE
epan/dissectors/packet-websocket.c in the WebSocket dissector in Wireshark 1.12.x before 1.12.5 uses a recursive algorithm, which allows remote attackers to cause a denial of service (CPU consumption) via a crafted packet.
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Analysis
by VulDB Data Team • 05/17/2022
The vulnerability identified as CVE-2015-3810 represents a critical denial of service weakness within Wireshark's WebSocket protocol dissector. This issue affects Wireshark versions 1.12.x prior to 1.12.5, where the WebSocket dissector implementation contains a recursive algorithm that can be exploited by remote attackers to consume excessive CPU resources. The flaw specifically resides in the packet-websocket.c file within the epan/dissectors directory of the Wireshark source code, making it a core component of the network protocol analysis functionality.
The technical implementation of this vulnerability stems from the recursive nature of the WebSocket dissector's packet parsing algorithm. When processing specially crafted WebSocket packets, the dissector enters into a recursive parsing loop that can rapidly escalate CPU consumption to near 100% utilization. This recursive behavior occurs because the dissector fails to properly validate or limit the depth of nested WebSocket frames during protocol analysis. The flaw demonstrates characteristics consistent with CWE-674, which describes "Uncontrolled Recursion" as a vulnerability where recursive calls are not properly bounded or validated, leading to resource exhaustion.
From an operational perspective, this vulnerability presents a significant risk to network monitoring and analysis environments that rely on Wireshark for protocol inspection. Attackers can exploit this weakness by crafting malicious WebSocket packets that trigger the recursive parsing behavior, potentially causing network analysis tools to become unresponsive or crash entirely. The impact extends beyond simple service disruption as it can affect network troubleshooting capabilities, security monitoring systems, and forensic analysis operations that depend on stable Wireshark performance. This vulnerability particularly threatens enterprise environments where Wireshark is used extensively for network traffic analysis and security incident response activities.
The exploitation of this vulnerability aligns with ATT&CK technique T1498, which covers "Network Denial of Service" attacks that consume system resources. Organizations utilizing Wireshark for network traffic analysis should consider this vulnerability as part of their broader network security posture assessment. The recommended mitigation strategy involves upgrading to Wireshark version 1.12.5 or later, which contains the patched WebSocket dissector implementation that eliminates the recursive algorithm and implements proper recursion depth limiting. Additionally, network administrators should implement monitoring for unusual CPU consumption patterns in network analysis tools and consider implementing network segmentation or packet filtering rules that limit exposure to potentially malicious WebSocket traffic while maintaining operational security.