CVE-2024-12397 is a vulnerability identified in the Quarkus-HTTP component, where the HTTP request parser incorrectly handles cookies containing specific value-delimiting characters. This parsing inconsistency is a form of HTTP Request/Response Smuggling, allowing attackers to manipulate how cookies are interpreted by the server. By crafting specially formatted cookie values, an attacker can exfiltrate HttpOnly cookies, which are normally inaccessible via client-side scripts, or inject arbitrary cookie values. This can lead to unauthorized access to sensitive session information or modification of cookie data, undermining the confidentiality and integrity of user sessions. The vulnerability has a CVSS 3.1 score of 7.4, indicating high severity, with network attack vector, no privileges or user interaction required, but high attack complexity due to the need for precise request crafting. The flaw affects all versions of Quarkus-HTTP prior to the patch (version details unspecified). While no active exploits have been reported, the potential for data leakage and session hijacking is significant, especially in environments where Quarkus is used to build cloud-native Java applications. The vulnerability highlights the risks of inconsistent HTTP parsing and the importance of robust input validation in web frameworks.

For European organizations, this vulnerability poses a significant risk to web applications built on Quarkus or using Quarkus-HTTP as part of their HTTP stack. Successful exploitation can lead to unauthorized disclosure of HttpOnly cookies, which often contain session tokens or authentication credentials, enabling attackers to hijack user sessions or impersonate users. This compromises data confidentiality and integrity, potentially leading to data breaches, unauthorized transactions, or manipulation of user data. The impact is particularly critical for sectors handling sensitive personal data, such as finance, healthcare, and government services, which are heavily regulated under GDPR. Additionally, the vulnerability could undermine trust in digital services and result in regulatory penalties if exploited. The high attack complexity somewhat limits widespread exploitation but does not eliminate risk, especially from skilled attackers targeting high-value assets. The absence of known exploits in the wild provides a window for mitigation before active attacks emerge.

European organizations should immediately identify and inventory all applications and services using Quarkus-HTTP and verify their versions. Applying vendor patches or updates that address CVE-2024-12397 is the primary mitigation step once available. In the interim, organizations should implement strict input validation and sanitization of HTTP headers and cookies to detect and block suspicious delimiter characters or malformed cookie values. Web Application Firewalls (WAFs) should be configured or updated with rules to detect HTTP request smuggling patterns and anomalous cookie manipulations. Monitoring HTTP traffic for unusual cookie behavior or unexpected header sequences can help detect exploitation attempts. Additionally, enforcing secure cookie attributes (Secure, HttpOnly, SameSite) and minimizing cookie scope reduces the attack surface. Security teams should conduct penetration testing focused on HTTP request parsing inconsistencies to validate defenses. Finally, raising developer awareness about secure HTTP parsing and cookie handling in Quarkus applications is essential to prevent similar vulnerabilities.