CVE-2024-6162 is a vulnerability in the Undertow web server's AJP (Apache JServ Protocol) listener component. The issue arises because the same buffer is reused to decode URL-encoded request paths for multiple concurrent requests. When multiple requests arrive simultaneously, the shared buffer leads to race conditions where the decoded path information from one request can overwrite or mix with another. This causes the server to process incorrect path data, resulting in errors such as "404 Not Found" or other application-level failures. The flaw does not directly expose sensitive data or allow unauthorized access but disrupts normal request handling, potentially causing denial of service (DoS) by making legitimate resources inaccessible. The vulnerability affects Undertow versions from 0 up to 2.3.0.Alpha1. It requires no privileges or user interaction to exploit, and the attack vector is network-based (remote). The CVSS v3.1 base score is 7.5, reflecting high severity due to the ease of exploitation and impact on availability. No known public exploits have been reported yet. The root cause is a concurrency bug in buffer management during URL decoding in the AJP listener, a protocol commonly used to connect web servers with application servers. This vulnerability highlights the risks of shared mutable state in concurrent request processing within web server components.

The primary impact of CVE-2024-6162 is denial of service caused by incorrect request path processing. Legitimate requests may fail with 404 errors or other application failures, disrupting service availability. This can degrade user experience, cause downtime, and potentially impact business operations relying on web applications served via Undertow with AJP enabled. While confidentiality and integrity are not directly affected, the availability impact can be significant for high-traffic or critical systems. Organizations running Undertow in production environments, especially those exposing AJP listeners to untrusted networks, face increased risk. The flaw could be exploited by attackers to cause persistent service disruption or intermittent failures, complicating troubleshooting and incident response. The lack of authentication or user interaction requirements lowers the barrier for exploitation, increasing the threat level. Overall, the vulnerability poses a moderate to high operational risk, particularly for enterprises relying on Undertow for Java-based web services.

To mitigate CVE-2024-6162, organizations should apply patches or updates from Undertow maintainers as soon as they become available, upgrading beyond version 2.3.0.Alpha1 where the issue is resolved. In the absence of immediate patches, disabling the AJP listener or restricting its network exposure to trusted internal networks can reduce attack surface. Implementing strict network segmentation and firewall rules to limit access to the AJP port is recommended. Additionally, monitoring logs for unusual 404 errors or application failures may help detect exploitation attempts. Reviewing concurrent request handling configurations and applying rate limiting or connection throttling can reduce the likelihood of triggering the concurrency bug. Developers and administrators should audit their Undertow configurations to ensure no unnecessary AJP usage and consider alternative protocols if feasible. Finally, maintaining robust incident response plans to quickly address service disruptions caused by this vulnerability is advisable.