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. The vulnerability specifically arises in the genrb binary, which is part of ICU's resource bundle generation tools. The flaw occurs in the SRBRoot::addTag function when processing the 'subtag' struct, where a buffer copy operation is performed without adequate size checking. This classic buffer overflow can lead to memory corruption, which attackers can leverage to execute arbitrary code locally. The vulnerability affects Red Hat Enterprise Linux 10, as ICU is included in its software stack. According to the CVSS v3.1 vector (AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H), exploitation requires local access, high attack complexity, no privileges, and user interaction, with impacts on confidentiality, integrity, and availability. No public exploits are known at this time, but the potential for local privilege escalation or code execution exists if exploited. The vulnerability was published on May 27, 2025, and is classified as high severity. The absence of patches at the time of reporting necessitates proactive mitigation. ICU's role in Unicode processing means that any application or service relying on it for localization or internationalization could be indirectly affected if the genrb tool is used or accessible.

For European organizations, the impact of CVE-2025-5222 could be significant in environments running Red Hat Enterprise Linux 10, particularly where ICU is used for Unicode processing in critical applications. Successful exploitation could allow attackers with local access to execute arbitrary code, potentially leading to unauthorized data access, system compromise, or disruption of services. This is especially concerning for sectors such as finance, government, telecommunications, and critical infrastructure, where data confidentiality and system integrity are paramount. Although remote exploitation is not feasible, insider threats or attackers who gain initial footholds could leverage this vulnerability for privilege escalation or lateral movement. The memory corruption could also cause system instability or denial of service, impacting availability. Given the high confidentiality, integrity, and availability impacts, organizations must prioritize addressing this vulnerability to maintain operational security and compliance with European data protection regulations.

1. Monitor Red Hat and ICU project advisories closely and apply official patches or updates as soon as they become available to remediate the vulnerability. 2. Restrict local access to systems running Red Hat Enterprise Linux 10, especially limiting access to the genrb binary and ICU-related tools to trusted administrators only. 3. Employ application whitelisting and endpoint protection solutions to detect and prevent unauthorized execution of potentially malicious code locally. 4. Conduct regular audits of user privileges and remove unnecessary local user accounts to reduce the attack surface. 5. Implement strict user interaction policies and educate users about the risks of executing untrusted binaries or scripts that might trigger this vulnerability. 6. Use security monitoring and intrusion detection systems to identify anomalous behavior indicative of exploitation attempts, such as unusual genrb usage or memory corruption symptoms. 7. Consider containerization or sandboxing of ICU-related tools to limit the impact of potential exploitation. 8. Maintain comprehensive backups and incident response plans to quickly recover from any compromise resulting from exploitation.