CVE-2025-36407 is a vulnerability identified in IBM Db2 for Linux, UNIX, and Windows, including Db2 Connect Server, specifically affecting versions 11.5.0 through 11.5.9 and 12.1.0 through 12.1.3. The root cause is improper validation of specified quantity in input, categorized under CWE-1284, which relates to insufficient neutralization of special elements in data query logic. This flaw allows a local user with privileges on the system to craft malicious input that can disrupt the normal processing of database queries, leading to a denial of service condition. The vulnerability does not require user interaction and can be exploited with low complexity, but it does require local access with some privileges. The impact is limited to availability, as confidentiality and integrity are not affected. No public exploits have been reported yet, but the medium CVSS score of 6.5 reflects the potential for service disruption in critical database environments. IBM has not yet published patches, but organizations should monitor for updates. The vulnerability highlights the importance of robust input validation in database query processing to prevent service outages caused by malformed or malicious inputs.

For European organizations, the primary impact of CVE-2025-36407 is the potential for denial of service on critical IBM Db2 database servers. This can lead to downtime of business-critical applications relying on Db2, affecting operational continuity, especially in sectors such as finance, manufacturing, telecommunications, and public services where Db2 is widely used. The disruption could result in loss of productivity, delayed services, and potential financial losses. Since the vulnerability requires local access, the risk is higher in environments where multiple users have local privileges or where insider threats exist. The lack of impact on confidentiality and integrity reduces the risk of data breaches, but availability interruptions can still have significant operational consequences. European organizations with complex IT environments and regulatory requirements for service availability must prioritize addressing this vulnerability to maintain compliance and service reliability.

1. Monitor IBM security advisories closely and apply official patches or updates as soon as they become available for affected Db2 versions. 2. Restrict local user access on Db2 servers to only trusted and necessary personnel to minimize the risk of exploitation. 3. Implement strict access controls and auditing on systems hosting Db2 to detect and prevent unauthorized local activity. 4. Employ application whitelisting and endpoint protection to reduce the risk of malicious input being introduced by local users. 5. Conduct regular security reviews and vulnerability assessments focusing on database input validation and privilege management. 6. Consider upgrading to later versions of IBM Db2 that may have addressed this vulnerability or improved input validation mechanisms. 7. Develop and test incident response plans to quickly recover from potential denial of service events affecting database availability.