CVE-2023-52602 is a high-severity vulnerability affecting the Linux kernel's JFS (Journaled File System) implementation. The flaw arises from an out-of-bounds read in the dtSearch function, which is responsible for searching the current page in the sorted entry table of a page. Specifically, the vulnerability occurs because the code lacks proper boundary checks when accessing the slab allocator's memory, leading to a potential slab-out-of-bounds read. This type of memory access error can cause undefined behavior, including kernel crashes or information leakage. The patch for this vulnerability introduces a boundary check to prevent out-of-bounds access and sets the return code to -EIO (Input/Output error) to handle error conditions gracefully. The CVSS v3.1 score is 7.8, indicating a high severity with the vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, meaning the attack requires local access with low complexity, low privileges, no user interaction, and impacts confidentiality, integrity, and availability significantly. Although no known exploits are currently reported in the wild, the vulnerability's nature and impact make it a critical issue for systems running vulnerable Linux kernel versions, especially those using the JFS filesystem. The CWE classification is CWE-400, which relates to uncontrolled resource consumption, suggesting that exploitation might lead to resource exhaustion or denial of service. The vulnerability was published on March 6, 2024, and affects multiple kernel versions identified by the same commit hash, indicating a specific code state before the patch was applied.

For European organizations, the impact of CVE-2023-52602 can be substantial, particularly for enterprises and service providers relying on Linux servers with JFS filesystems. The vulnerability can lead to kernel crashes (denial of service), unauthorized information disclosure, and potential privilege escalation if combined with other vulnerabilities. This can disrupt critical services, including web hosting, cloud infrastructure, and internal enterprise applications. Confidential data stored on affected systems could be exposed, violating data protection regulations such as GDPR. The high severity and local attack vector mean that insiders or attackers with limited access could exploit this flaw to escalate their privileges or disrupt operations. Organizations in sectors like finance, healthcare, telecommunications, and government, which often use Linux-based infrastructure, may face operational downtime and reputational damage. Additionally, the lack of known exploits currently does not preclude future weaponization, so proactive mitigation is essential to avoid exploitation in the European threat landscape.

European organizations should prioritize patching affected Linux kernel versions by applying the official fixes that add boundary checks in the JFS dtSearch function. Since the vulnerability requires local access, organizations should also enforce strict access controls and limit user privileges to reduce the attack surface. Monitoring and auditing local user activities can help detect suspicious behavior indicative of exploitation attempts. For systems where immediate patching is not feasible, disabling or avoiding the use of the JFS filesystem can mitigate risk. Additionally, implementing kernel-level security modules such as SELinux or AppArmor with strict policies can help contain potential exploitation. Regular vulnerability scanning and updating asset inventories to identify affected systems will aid in timely remediation. Backup strategies should be reviewed to ensure data integrity and availability in case of denial-of-service incidents. Finally, educating system administrators about this vulnerability and its implications will improve incident response readiness.