CVE-2024-27982 identifies a vulnerability in the HTTP server component of NodeJS versions 4.0 through 21.0, where malformed HTTP headers containing a space before the Content-Length header are not parsed correctly. This parsing flaw enables HTTP request smuggling (CWE-444), a technique where an attacker crafts a single HTTP request that is interpreted as two separate requests by the server and any intermediate proxies. Specifically, the server fails to recognize the Content-Length header properly if it is preceded by a space, allowing an attacker to smuggle a second HTTP request within the body of the first. This can lead to request desynchronization between front-end proxies and back-end servers, enabling various attacks such as cache poisoning, cross-user request forgery, and bypassing security controls. The vulnerability requires no privileges or user interaction, making it easier to exploit remotely over the network. Although no known exploits are currently in the wild, the flaw affects a broad range of NodeJS versions, including many actively used in production environments. The CVSS v3.0 score is 6.5 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and impacts on integrity and availability but not confidentiality. The vulnerability was reserved in February 2024 and published in May 2024, with no patch links currently available, indicating that remediation is pending or in progress. This vulnerability is critical for developers and organizations relying on NodeJS HTTP servers, as it undermines the reliability of HTTP request parsing and can be leveraged for advanced web attacks.

For European organizations, the impact of CVE-2024-27982 can be significant, especially for those relying on NodeJS for web applications, APIs, and microservices. HTTP request smuggling can lead to unauthorized request manipulation, allowing attackers to bypass security controls, poison caches, hijack user sessions, or cause denial of service by desynchronizing requests. This can compromise the integrity and availability of web services, potentially disrupting business operations and exposing sensitive data indirectly. Organizations in sectors such as finance, healthcare, e-commerce, and government services, which often use NodeJS for scalable web infrastructure, may face increased risk. The vulnerability's network accessibility and lack of required authentication increase the attack surface, making public-facing services particularly vulnerable. Additionally, the complexity of detecting HTTP request smuggling attacks means that organizations might not be aware of exploitation attempts, increasing the risk of prolonged undetected compromise. The absence of known exploits in the wild currently provides a window for proactive mitigation, but the widespread use of NodeJS in Europe necessitates urgent attention to avoid future exploitation.

1. Monitor NodeJS official channels for patches addressing CVE-2024-27982 and apply updates promptly once available. 2. In the interim, implement strict input validation and sanitization on HTTP headers at the application and proxy levels to detect and reject malformed headers, especially those with irregular spacing before Content-Length. 3. Deploy or update Web Application Firewalls (WAFs) and reverse proxies with rules specifically designed to detect and block HTTP request smuggling attempts, including anomalies in header parsing and request length inconsistencies. 4. Conduct thorough security testing, including fuzzing and penetration testing focused on HTTP request parsing, to identify potential exploitation vectors in your environment. 5. Segment network architecture to limit the impact of potential request smuggling attacks, ensuring that compromised services cannot easily propagate attacks to critical backend systems. 6. Educate development and operations teams about the risks of HTTP request smuggling and encourage secure coding practices that avoid reliance on vulnerable HTTP parsing behaviors. 7. Monitor logs and network traffic for unusual patterns indicative of request smuggling, such as unexpected request sequences or header anomalies. 8. Consider temporary mitigation by configuring front-end proxies or load balancers to normalize HTTP headers and reject suspicious requests until patches are applied.