CVE-2025-2668 identifies a denial of service (DoS) vulnerability in IBM Db2 for Linux, UNIX, and Windows, specifically versions 11.5.0 through 11.5.9, including Db2 Connect Server. The root cause is related to CWE-789, which involves uncontrolled memory allocation or resource exhaustion. An authenticated user can craft a malicious query that triggers excessive resource consumption, causing the Db2 server process to crash and become unavailable. This vulnerability does not compromise data confidentiality or integrity but directly impacts the availability of the database service. The attack vector requires network access with valid credentials, and no user interaction beyond authentication is necessary. The CVSS v3.1 base score of 6.5 reflects the medium severity, with attack vector network (AV:N), low attack complexity (AC:L), privileges required (PR:L), no user interaction (UI:N), and impact limited to availability (A:H). No public exploits have been reported yet, and IBM has not published patches at the time of this report. Organizations using affected Db2 versions should monitor IBM advisories closely and prepare to deploy updates promptly. The vulnerability could be exploited internally or by compromised accounts, emphasizing the importance of strict access controls and monitoring.

For European organizations, this vulnerability poses a risk of service disruption in critical database environments running IBM Db2 11.5.x. The denial of service could interrupt business operations, data processing, and applications dependent on Db2, potentially causing financial losses and operational delays. Sectors such as finance, manufacturing, telecommunications, and government agencies that rely heavily on IBM Db2 for transactional and analytical workloads are particularly vulnerable. The requirement for authenticated access reduces the risk from external attackers but increases the threat from insider misuse or compromised credentials. Prolonged downtime could affect compliance with data availability regulations and service level agreements. Given the widespread use of IBM Db2 in Europe, especially in large enterprises and public sector organizations, the impact could be significant if not mitigated promptly.

1. Apply official patches from IBM as soon as they become available to address the vulnerability directly. 2. Until patches are released, restrict Db2 server access to trusted and essential personnel only, minimizing the number of authenticated users. 3. Implement strict role-based access controls (RBAC) to limit query execution privileges to necessary users and applications. 4. Monitor database logs and network traffic for unusual query patterns or spikes in resource usage that could indicate exploitation attempts. 5. Employ database activity monitoring tools to detect and alert on anomalous behavior from authenticated users. 6. Consider deploying rate limiting or query complexity restrictions to prevent resource exhaustion from crafted queries. 7. Regularly review and rotate credentials to reduce the risk of compromised accounts being used to exploit this vulnerability. 8. Maintain robust incident response plans to quickly recover from potential denial of service events affecting Db2 services.