CVE-2024-6162 is a vulnerability identified in the Undertow web server component, specifically affecting its AJP (Apache JServ Protocol) listener. The issue arises from the mishandling of URL-encoded request paths during concurrent requests. Undertow uses a shared buffer to decode these paths, but when multiple requests are processed simultaneously, this buffer is reused improperly, causing path information to become corrupted or mixed between requests. This results in the server attempting to access incorrect resource paths, leading to errors such as HTTP 404 Not Found or other application-level failures. The root cause is a race condition or concurrency flaw in the buffer management for path decoding. The vulnerability does not impact confidentiality or integrity directly but severely affects availability by causing denial of service conditions where legitimate resources are unreachable. The vulnerability affects Undertow versions from 0 up to 2.3.0.Alpha1 and has a CVSS v3.1 score of 7.5, indicating high severity. Exploitation requires no privileges or user interaction and can be triggered remotely by sending crafted concurrent requests to the AJP listener. No public exploits are known at this time, but the flaw's nature makes it a credible risk for service disruption in environments using Undertow as a web server or reverse proxy, especially where AJP is enabled for backend communication.

For European organizations, the primary impact of CVE-2024-6162 is on service availability. Enterprises relying on Undertow for web applications or as part of Java-based middleware stacks may experience denial of service, disrupting business-critical services and customer-facing applications. This can lead to operational downtime, loss of revenue, and reputational damage. Public sector entities and critical infrastructure providers using Undertow could face increased risk of service outages, which may affect citizen services and compliance with service-level agreements. The vulnerability does not expose sensitive data or allow unauthorized access, but the disruption caused by resource misallocation and path confusion can cascade into broader application failures. Organizations with high concurrency web environments are particularly vulnerable, as the flaw manifests under simultaneous request loads. Given the remote exploitability and lack of required authentication, attackers can easily trigger the issue, increasing the threat level for European businesses with exposed AJP listeners.

To mitigate CVE-2024-6162, European organizations should first verify if Undertow versions in use fall within the affected range (up to 2.3.0.Alpha1). Immediate steps include disabling the AJP listener if not strictly necessary, as this reduces the attack surface. If AJP is required, limit the number of concurrent requests to the listener to reduce the risk of buffer contention. Network-level controls such as firewall rules or access control lists should restrict access to the AJP port to trusted internal systems only. Monitoring and logging of AJP traffic can help detect anomalous request patterns indicative of exploitation attempts. Organizations should track vendor advisories for patches or updates that address this concurrency flaw and apply them promptly once available. Additionally, consider deploying web application firewalls (WAFs) capable of detecting malformed or suspicious URL-encoded requests targeting the AJP listener. Conduct thorough testing in staging environments to ensure that mitigations do not disrupt legitimate traffic. Finally, educate development and operations teams about the concurrency risks inherent in shared buffer usage and encourage secure coding and configuration practices.