CVE-2025-5222 is a stack-based buffer overflow vulnerability identified in the International Components for Unicode (ICU) library, a widely used set of C/C++ and Java libraries providing Unicode and globalization support for software applications. The flaw exists in the genrb binary, which is part of ICU's resource bundle generation tools. Specifically, the vulnerability arises in the SRBRoot::addTag function where the 'subtag' struct is copied without proper size validation, leading to a classic buffer overflow on the stack. This unchecked buffer copy can cause memory corruption, which attackers with local access could leverage to execute arbitrary code with the privileges of the user running the genrb binary. The vulnerability affects Red Hat Enterprise Linux 10, a major enterprise Linux distribution, indicating that systems running this OS version and utilizing ICU are at risk. The CVSS 3.1 base score is 7.0, reflecting high severity due to the potential for full compromise of confidentiality, integrity, and availability, despite the requirement for local access (AV:L), high attack complexity (AC:H), no privileges required (PR:N), and user interaction (UI:R). No public exploits are known yet, but the vulnerability's nature makes it a significant risk for environments where local users or processes can invoke genrb. The issue was published on May 27, 2025, and is assigned by Red Hat, but no patch links are currently provided, indicating that remediation may still be pending or in progress.

For European organizations, the impact of CVE-2025-5222 can be substantial, particularly in sectors relying on Red Hat Enterprise Linux 10 for critical infrastructure, such as finance, telecommunications, government, and manufacturing. Successful exploitation could allow local attackers or malicious insiders to execute arbitrary code, potentially leading to privilege escalation, data breaches, or disruption of services. Since ICU is integral to Unicode processing, any compromise could affect applications handling internationalization, potentially impacting data integrity and availability of localized services. The requirement for local access and user interaction limits remote exploitation but does not eliminate risk, especially in environments with multiple users or where attackers have gained initial footholds. Memory corruption could also lead to system crashes, affecting availability. The absence of known exploits reduces immediate risk but underscores the need for proactive mitigation to prevent future exploitation attempts.

1. Monitor Red Hat and ICU project advisories closely and apply official patches immediately once released to address CVE-2025-5222. 2. Restrict access to systems running Red Hat Enterprise Linux 10, especially limiting local user accounts that can execute or invoke the genrb binary or related ICU tools. 3. Implement strict user privilege management to minimize the number of users with local access rights capable of triggering the vulnerability. 4. Employ application whitelisting or execution control to prevent unauthorized execution of genrb or related binaries. 5. Use security monitoring tools to detect anomalous local activity, such as unexpected execution of ICU tools or unusual memory corruption indicators. 6. Conduct regular security audits and vulnerability scans focusing on ICU components and related binaries. 7. Consider isolating critical systems or running them in hardened containers or virtual machines to limit the impact of potential local exploits. 8. Educate users about the risks of executing untrusted binaries or scripts that might invoke vulnerable components requiring user interaction.