CVE-2024-22019 in Node.js
Summary
by MITRE • 02/20/2024
A vulnerability in Node.js HTTP servers allows an attacker to send a specially crafted HTTP request with chunked encoding, leading to resource exhaustion and denial of service (DoS). The server reads an unbounded number of bytes from a single connection, exploiting the lack of limitations on chunk extension bytes. The issue can cause CPU and network bandwidth exhaustion, bypassing standard safeguards like timeouts and body size limits.
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Analysis
by VulDB Data Team • 02/14/2025
This vulnerability resides within the Node.js HTTP server implementation and represents a critical resource exhaustion flaw that can be exploited through crafted chunked encoding requests. The vulnerability specifically targets the HTTP parser's handling of chunked transfer encoding where the server fails to enforce reasonable limits on the number of bytes that can be read from a single connection during the chunk extension processing phase. This allows attackers to craft requests that cause the server to continuously read data without proper bounds, effectively creating a resource exhaustion condition that can lead to complete service disruption.
The technical flaw manifests when Node.js processes HTTP requests using chunked transfer encoding, a standard mechanism for transferring data in chunks without specifying the total content length upfront. During this process, the HTTP parser reads chunk extension bytes that provide metadata about the chunk size and any additional parameters. The vulnerability occurs because the parser does not implement proper bounds checking on these extension bytes, allowing an attacker to send requests with malformed or excessively long chunk extensions that cause the server to consume unlimited resources. This behavior directly violates the principle of least privilege and resource management that should be inherent in any robust server implementation.
The operational impact of this vulnerability extends beyond simple service disruption to encompass significant performance degradation and potential system compromise. Attackers can leverage this flaw to exhaust CPU cycles through continuous parsing operations and consume network bandwidth by sending large amounts of data that the server attempts to process. The vulnerability's effectiveness stems from its ability to bypass standard DoS protection mechanisms such as connection timeouts and body size limits that are typically configured to prevent resource exhaustion attacks. This makes it particularly dangerous because it can overwhelm systems even when traditional safeguards are properly configured, as the attack targets the parsing layer rather than the application layer where most protections are implemented.
The vulnerability aligns with CWE-770, which addresses the allocation of resources without proper limits or bounds, and demonstrates how improper resource management can lead to denial of service conditions. From an ATT&CK framework perspective, this represents a resource exhaustion technique that can be categorized under T1499.004 for network denial of service and T1595.001 for reconnaissance through information gathering. The attack vector specifically maps to T1190 for exploitation of vulnerabilities in network services and T1071.004 for application layer protocols. Organizations implementing Node.js applications should consider this vulnerability as a critical risk that requires immediate attention, particularly in environments where external access to HTTP servers is permitted without proper network segmentation or additional protective measures.
Mitigation strategies should include immediate application of Node.js security patches that implement proper bounds checking on chunk extension bytes and limit the number of bytes that can be read from a single connection during chunked transfer encoding processing. Network-level protections such as rate limiting and connection tracking should be implemented to detect and prevent abnormal patterns of chunked request processing. Additionally, organizations should configure their HTTP servers to enforce strict limits on request sizes, connection timeouts, and maximum number of concurrent connections to prevent exploitation. System monitoring should be enhanced to detect unusual CPU and memory consumption patterns that may indicate exploitation attempts. Regular security audits should verify that chunked encoding processing is properly bounded and that no custom implementations bypass the standard HTTP parser protections. The vulnerability serves as a reminder of the critical importance of proper resource bounds checking in network service implementations and the need for comprehensive security testing that includes edge case scenarios involving protocol parsing.