CVE-2014-0193 in Netty
Summary
by MITRE
WebSocket08FrameDecoder in Netty 3.6.x before 3.6.9, 3.7.x before 3.7.1, 3.8.x before 3.8.2, 3.9.x before 3.9.1, and 4.0.x before 4.0.19 allows remote attackers to cause a denial of service (memory consumption) via a TextWebSocketFrame followed by a long stream of ContinuationWebSocketFrames.
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Analysis
by VulDB Data Team • 01/11/2026
The vulnerability identified as CVE-2014-0193 represents a critical memory exhaustion issue within the Netty networking framework, specifically affecting WebSocket protocol handling in versions prior to the mentioned secure releases. This flaw exists in the WebSocket08FrameDecoder component which is responsible for parsing WebSocket frames according to the draft 08 specification. The vulnerability stems from insufficient input validation and memory management when processing WebSocket frames, creating a pathway for remote attackers to exploit memory consumption patterns that can lead to system instability and service disruption.
The technical implementation of this vulnerability occurs through a specific sequence of WebSocket frame types that manipulate the decoder's internal state machine. An attacker can initiate a connection with a TextWebSocketFrame followed by an extended series of ContinuationWebSocketFrames, which causes the decoder to continuously allocate memory buffers without proper bounds checking. This memory allocation pattern creates a gradual but sustained consumption of system resources, ultimately leading to memory exhaustion on the affected server. The flaw is particularly insidious because it does not immediately crash the system but rather consumes memory over time until the service becomes unresponsive or crashes entirely.
From an operational perspective, this vulnerability presents a significant risk to applications relying on Netty for WebSocket communication, particularly in high-traffic environments where memory resources are already constrained. The denial of service impact can affect web applications, real-time communication systems, chat platforms, and any service that utilizes WebSocket protocols for bidirectional communication. The vulnerability affects multiple major versions of Netty including the 3.6.x, 3.7.x, 3.8.x, 3.9.x, and 4.0.x release lines, indicating a widespread exposure across the framework's ecosystem. Attackers can exploit this without requiring authentication or specialized privileges, making it particularly dangerous in environments where WebSocket services are publicly accessible.
The vulnerability maps directly to CWE-400, which addresses "Uncontrolled Resource Consumption," and aligns with ATT&CK technique T1499.004 for "Network Denial of Service" within the adversary tactics framework. Organizations should immediately implement mitigations including upgrading to the patched versions of Netty, implementing rate limiting for WebSocket connections, and monitoring memory consumption patterns for anomalous behavior. Additionally, network-level protections such as connection throttling and frame size restrictions can provide additional defense in depth. The security community should also consider implementing automated patch management systems to ensure rapid deployment of security updates across all affected systems, as this vulnerability demonstrates how seemingly minor protocol handling flaws can create substantial operational risks in production environments.