CVE-2024-49568 is a vulnerability identified in the Linux kernel's net/smc (Shared Memory Communications) subsystem. The issue arises when the Linux kernel server receives a proposal message from a remote client. Specifically, the fields v2_ext_offset, eid_cnt, and ism_gid_cnt within the proposal message are sourced from the remote client and cannot be fully trusted. The vulnerability occurs because the kernel does not properly validate these fields before using them. In particular, if the v2_ext_offset field exceeds its maximum expected value, it can lead to an out-of-bounds memory access. This improper validation can cause the kernel to access incorrect memory addresses, potentially resulting in a system crash (denial of service). The vulnerability is addressed by a patch that adds checks on the v2_ext_offset, eid_cnt, and ism_gid_cnt fields before they are used, preventing invalid memory access. This vulnerability does not have any known exploits in the wild as of the published date, and no CVSS score has been assigned yet. The affected versions are specific Linux kernel commits identified by the hash 8c3dca341aea885249e08856c4380300b75d2cf5. The vulnerability affects the Linux kernel, which is widely used in servers, desktops, and embedded devices globally.

For European organizations, this vulnerability could have significant implications, especially for those relying on Linux-based servers and infrastructure. Exploitation could lead to kernel crashes, causing denial of service conditions that disrupt critical services and operations. This is particularly impactful for sectors such as finance, telecommunications, healthcare, and government services where uptime and reliability are crucial. Although there is no indication of privilege escalation or remote code execution, the denial of service could be leveraged as part of a larger attack chain or to disrupt services during critical periods. Additionally, organizations using Linux in embedded systems or industrial control systems could face operational disruptions. The lack of known exploits reduces immediate risk, but the widespread use of Linux means that unpatched systems remain vulnerable to potential future exploitation. The vulnerability requires a malicious client to send crafted proposal messages, so exposure depends on network architecture and whether untrusted clients can interact with the vulnerable service.

European organizations should prioritize applying the official Linux kernel patch that validates the v2_ext_offset, eid_cnt, and ism_gid_cnt fields in the net/smc subsystem. System administrators should: 1) Identify all Linux systems running affected kernel versions and plan for timely updates. 2) Deploy kernel updates from trusted sources or Linux distribution vendors that include the patch. 3) Restrict network access to services using the net/smc protocol, limiting exposure to untrusted clients. 4) Implement network segmentation and firewall rules to prevent unauthorized clients from sending proposal messages to vulnerable servers. 5) Monitor system logs and kernel crash reports for signs of exploitation attempts or unusual behavior. 6) For critical infrastructure, consider additional runtime protections such as kernel hardening and intrusion detection systems that can detect anomalous network messages or kernel faults. 7) Maintain an inventory of Linux kernel versions in use and subscribe to security advisories for timely awareness of patches and exploits.