CVE-2024-50258 is a vulnerability identified in the Linux kernel networking subsystem related to the handling of Generic Segmentation Offload (GSO) parameters, specifically gso_max_size and gso_ipv4_max_size. The issue arises when these configuration parameters are set to very small values, which leads to an integer underflow in the function sk_dst_gso_max_size(). This underflow causes the kernel to compute an incorrect, excessively large value for sk->sk_gso_max_size, exceeding device limits. During TCP transmission, this miscalculation triggers a BUG_ON condition, resulting in a kernel crash (panic). The crash occurs in the call stack involving tcp_write_xmit, tcp_init_tso_segs, tcp_set_skb_tso_segs, and tcp_skb_pcount_set functions, where the calculation of tso_segs (TCP Segmentation Offload segments) underflows due to the division of skb->len by mss_now. The vulnerability is rooted in improper validation of the minimum allowed values for gso_max_size and gso_ipv4_max_size, which has been addressed by adding checks to prevent such small values. This flaw can cause a denial of service (DoS) by crashing the kernel when processing network packets with specific offload configurations. There is no indication of code execution or privilege escalation, and no known exploits are reported in the wild as of the publication date. The affected versions are various Linux kernel builds prior to the patch, and the vulnerability was publicly disclosed on November 9, 2024.

For European organizations, this vulnerability poses a risk primarily in environments running Linux kernels with customized or misconfigured GSO parameters, particularly in network-intensive systems such as data centers, cloud infrastructure, telecommunications equipment, and enterprise servers. A successful exploitation leads to a kernel crash, causing system downtime and potential disruption of critical services. This can impact availability of network services, leading to operational interruptions and potential financial losses. While the vulnerability does not directly compromise confidentiality or integrity, the induced denial of service could be leveraged as part of a broader attack strategy to degrade service or distract from other malicious activities. Organizations relying on Linux-based network appliances or servers with high network throughput are particularly vulnerable if they have not applied the patch or do not enforce safe configuration defaults. The absence of known exploits reduces immediate risk, but the potential for accidental misconfiguration or targeted attacks exploiting this flaw remains a concern.

To mitigate this vulnerability, European organizations should: 1) Apply the latest Linux kernel patches that include the fix for CVE-2024-50258 as soon as possible to prevent exploitation. 2) Audit and validate network stack configurations, specifically the gso_max_size and gso_ipv4_max_size parameters, ensuring they are set to safe minimum values as recommended by the kernel maintainers. 3) Implement configuration management and monitoring to detect any unauthorized or accidental changes to these parameters. 4) Employ kernel crash monitoring and alerting to quickly identify and respond to any kernel panics potentially related to this issue. 5) For critical infrastructure, consider deploying network segmentation and redundancy to minimize the impact of potential DoS conditions caused by kernel crashes. 6) Engage in proactive vulnerability management and maintain up-to-date inventories of Linux kernel versions in use to prioritize patching efforts effectively.