CVE-2024-50123 is a vulnerability identified in the Linux kernel related to the Berkeley Packet Filter (BPF) subsystem, specifically concerning the handling of sockmap link file descriptors. The issue arises from an out-of-bounds read in the function bpf_link_show_fdinfo(), which is responsible for displaying file descriptor information for BPF links. The root cause is the absence of a required BPF_LINK_TYPE invocation for the sockmap link type, leading to improper handling of the sockmap link fd. This omission results in an out-of-bounds memory read, which could potentially cause information disclosure or kernel instability. The fix involves adding the missing BPF_LINK_TYPE invocation for the sockmap link and improving code comments to prevent similar oversights in the future. The vulnerability affects certain Linux kernel versions identified by the commit hash 699c23f02c65cbfc3e638f14ce0d70c23a2e1f02. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. This vulnerability is technical and low-level, impacting kernel memory safety in the BPF subsystem, which is widely used for network packet filtering and monitoring.

For European organizations, this vulnerability poses a risk primarily to systems running vulnerable Linux kernel versions with BPF sockmap functionality enabled. The out-of-bounds read could lead to information leakage from kernel memory or potentially cause kernel crashes, affecting system stability and availability. Organizations relying on Linux servers for critical infrastructure, cloud services, or network appliances could experience service disruptions or data exposure if exploited. Although no active exploits are known, the widespread use of Linux in European enterprises, government agencies, and telecommunications means that the vulnerability could be targeted once exploit code becomes available. The impact is heightened in environments where unprivileged users or containers have access to BPF features, as this could facilitate privilege escalation or lateral movement. The vulnerability does not appear to require user interaction but may require local access, limiting remote exploitation but still posing a significant risk in multi-tenant or shared environments.

European organizations should promptly apply the Linux kernel patches that address CVE-2024-50123 once they are released by their Linux distribution vendors. Until patches are available, organizations should consider disabling or restricting BPF sockmap functionality where feasible, especially in environments with untrusted users or containers. Implement strict access controls and kernel lockdown features to limit BPF usage to trusted processes. Monitoring kernel logs for unusual BPF-related activity can help detect exploitation attempts. Additionally, organizations should ensure that their Linux systems are running supported and updated kernel versions and maintain a robust patch management process. Network segmentation and container isolation can further reduce the risk of exploitation spreading within the network. Finally, security teams should stay informed about any emerging exploit developments related to this vulnerability.