CVE-2023-52483 is a use-after-free (UAF) vulnerability identified in the Linux kernel's MCTP (Management Component Transport Protocol) networking component. The root cause stems from the lack of proper synchronization during route lookups within the MCTP implementation. Specifically, the functions mctp_route_lookup and mctp_route_lookup_null traverse the network's route list without holding the Read-Copy-Update (RCU) read-side lock. This omission allows the route lookup process to be preempted, creating a race condition where the route pointer may be freed (kfree()) while still in use, leading to a UAF scenario. The vulnerability was discovered through analysis by Sili Luo from Huawei, who demonstrated that introducing a delay in the route lookup could trigger this UAF when sendmsg() operations and route deletions occur concurrently. The fix involves adding the appropriate RCU read-side critical section locks around route lookups to prevent preemption and concurrent freeing of route pointers. Other accesses to net->mctp.routes are already protected by RCU read locks or RTNL locks for updates, indicating this was a specific synchronization oversight. This vulnerability affects Linux kernel versions identified by the commit hash 889b7da23abf92faf34491df95733bda63639e32 and potentially other versions containing the same code pattern. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2023-52483 could be significant in environments relying on Linux-based systems that utilize the MCTP protocol, which is often employed in hardware management and communication in data centers, telecom infrastructure, and embedded systems. Exploitation of this vulnerability could allow an attacker with the ability to trigger concurrent sendmsg() and route deletion operations to cause a use-after-free condition, potentially leading to kernel crashes (denial of service) or, in a worst-case scenario, arbitrary code execution with kernel privileges. This could compromise the confidentiality, integrity, and availability of critical systems. Given the widespread use of Linux in European enterprise servers, cloud infrastructure, and embedded devices, the vulnerability poses a risk especially to sectors such as telecommunications, manufacturing, and critical infrastructure where MCTP might be in use. However, exploitation requires specific conditions and concurrency, which may limit the attack surface. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

European organizations should prioritize applying the official Linux kernel patches that introduce proper RCU read-side locking around MCTP route lookups. Since no patch links are provided in the source, organizations should track Linux kernel updates closely and deploy kernel upgrades from trusted vendors as soon as fixes are available. For environments where immediate patching is not feasible, organizations should audit and monitor systems for unusual kernel crashes or instability that could indicate exploitation attempts. Network segmentation and limiting access to systems that handle MCTP traffic can reduce exposure. Additionally, organizations should implement strict privilege separation and ensure that only authorized users and processes can perform operations that trigger route lookups or route deletions. Monitoring kernel logs and employing intrusion detection systems capable of identifying anomalous kernel behavior related to networking operations can provide early warning. Finally, organizations should engage with their Linux distribution vendors and hardware providers to confirm the presence of patches and coordinate timely updates.