CVE-2024-7885 is a concurrency vulnerability classified as a race condition in the Undertow web server, specifically within the ProxyProtocolReadListener component. The flaw arises because the parseProxyProtocolV1 method reuses the same StringBuilder instance across multiple HTTP requests processed on a single persistent connection. This shared mutable state without proper synchronization allows data from one request or response to bleed into another, causing unintended data exposure. The vulnerability can lead to errors, connection termination, and, more critically, leakage of sensitive information between requests. Undertow versions from 0 up to 2.3.0.Alpha1 are affected. The vulnerability has a CVSS 3.1 score of 7.5 (high), reflecting its network attack vector, low attack complexity, no privileges required, and no user interaction needed. Although no exploits are currently known in the wild, the risk is significant due to the potential confidentiality impact and the common use of Undertow in Java-based web applications and middleware. The flaw highlights the dangers of improper synchronization in concurrent request handling, especially in HTTP/1.1 persistent connections or HTTP/2 multiplexing scenarios where multiple requests share the same connection context.

For European organizations, this vulnerability poses a risk of sensitive data leakage between HTTP requests, which can compromise confidentiality and potentially expose private user or business information. The connection errors and terminations caused by this race condition can also degrade service availability and reliability, impacting user experience and operational continuity. Organizations relying on Undertow as part of their web infrastructure, particularly those handling sensitive or regulated data (e.g., financial, healthcare, or governmental sectors), face increased compliance and reputational risks. The vulnerability's network-exploitable nature means attackers can remotely trigger the issue without authentication, increasing the threat surface. Given the widespread use of Java middleware in Europe, especially in countries with strong enterprise IT sectors, the impact could be significant if left unmitigated.

1. Upgrade Undertow to a fixed version once the vendor releases a patch addressing CVE-2024-7885. Monitor official Undertow and Red Hat advisories for updates. 2. Until a patch is available, consider disabling HTTP persistent connections or limiting the number of requests per connection to reduce the risk of shared state across requests. 3. Implement strict request isolation by configuring connection handling to avoid reuse of mutable objects like StringBuilder across concurrent requests. 4. Employ runtime application self-protection (RASP) or web application firewalls (WAF) to detect and block anomalous request patterns that might exploit this race condition. 5. Conduct thorough code reviews and testing for concurrent request handling in custom Undertow integrations to identify and fix similar synchronization issues. 6. Monitor logs for unusual connection errors or data anomalies that could indicate exploitation attempts. 7. Educate development and operations teams about concurrency risks in web server components to prevent recurrence.