CVE-2024-42283 is a vulnerability identified in the Linux kernel's networking subsystem, specifically within the nexthop group (nexthop_grp) structure handling. The issue arises because two reserved fields within the nexthop_grp structure are not properly initialized by the function nla_put_nh_group(). As a result, these fields contain residual kernel memory data (garbage values) when nexthop groups are dumped or queried, for example via the 'ip nexthop get' command. Although these reserved fields are currently unused, their uninitialized state leads to unintended leakage of kernel memory contents to user space. This memory leakage could potentially expose sensitive kernel data, which may aid attackers in further exploitation or reconnaissance. The vulnerability does not directly allow code execution or privilege escalation but represents an information disclosure flaw. The root cause is a failure to zero-initialize all fields in the nexthop_grp structure before sending it to user space. The fix involves initializing these reserved fields to zero, preventing leakage of kernel memory contents. There are no known exploits in the wild at this time, and the vulnerability was published on August 17, 2024. The affected versions correspond to a specific Linux kernel commit hash, indicating the issue is present in certain recent kernel builds prior to the patch. No CVSS score has been assigned yet.

For European organizations, the primary impact of CVE-2024-42283 is the unintended disclosure of kernel memory contents through the networking subsystem. While the leaked data is from reserved fields and may not directly contain sensitive user data, it could reveal kernel pointers or other internal state information. This information disclosure can facilitate advanced attacks such as kernel address space layout randomization (KASLR) bypass or other kernel exploitation techniques. Organizations relying heavily on Linux-based infrastructure, including servers, network appliances, and cloud environments, could be at risk of attackers gaining valuable reconnaissance data to craft more effective attacks. However, since exploitation does not grant direct control or privilege escalation, the immediate risk is lower compared to more severe vulnerabilities. Nonetheless, in sensitive environments such as critical infrastructure, financial services, or government networks, even limited kernel memory leaks can be leveraged as part of multi-stage attack chains. The vulnerability affects Linux kernel versions used widely across Europe in enterprise and cloud deployments, so the potential exposure is broad. The lack of known exploits reduces urgency but does not eliminate risk, especially for high-value targets.

To mitigate CVE-2024-42283, European organizations should prioritize applying the official Linux kernel patches that initialize the reserved fields in the nexthop_grp structure to zero. This patch prevents kernel memory leakage by ensuring no residual data is exposed. Organizations should: 1) Identify all Linux systems running affected kernel versions, particularly those handling advanced networking features or using the 'ip nexthop' functionality. 2) Update these systems promptly to patched kernel versions provided by their Linux distribution vendors or compile and deploy the fixed kernel from source if necessary. 3) Restrict access to network configuration utilities and interfaces that can query nexthop groups to trusted administrators only, minimizing the risk of unauthorized information disclosure. 4) Monitor system logs and network activity for unusual queries or reconnaissance attempts targeting the networking stack. 5) Incorporate this vulnerability into vulnerability management and patching workflows to ensure timely remediation. Since no user interaction is required to trigger the information leak, network segmentation and strict access controls on management interfaces are critical additional defenses. Regularly auditing kernel versions and configurations will help prevent similar issues.