CVE-2023-52845 is a vulnerability identified in the Linux kernel's Transparent Inter-Process Communication (TIPC) subsystem, specifically related to the handling of bearer-related names passed through netlink interfaces. The root cause stems from the acceptance of non-null-terminated strings for bearer names, which are used to identify communication links within TIPC. The vulnerability arises because functions such as strlen() and strstr() are called on these bearer names without proper null-termination checks, leading to uninitialized memory reads and potential buffer overruns. The issue was detected by syzbot, a kernel fuzzing tool, which reported uninitialized value accesses in string handling functions within the kernel's string.c library. The vulnerability is triggered when a non-null-terminated bearer name is passed via netlink, causing the kernel to process potentially malformed strings. This can lead to memory corruption or information leakage. The patch for this vulnerability changes the netlink attribute policy (nla_policy) for bearer-related names from NLA_STRING to NLA_NUL_STRING, enforcing that only null-terminated strings are accepted, thereby preventing the buffer overrun and uninitialized memory access issues. The vulnerability affects multiple versions of the Linux kernel identified by the commit hash 0655f6a8635b1b66f2434d5556b1044c14b1ccaf. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. However, the technical details indicate a memory safety issue that could be leveraged under certain conditions to compromise kernel stability or leak sensitive information.

For European organizations, the impact of CVE-2023-52845 can be significant given the widespread use of Linux in enterprise servers, cloud infrastructure, and embedded systems. Exploitation of this vulnerability could lead to kernel memory corruption, potentially causing system crashes (denial of service) or information disclosure. In environments where Linux servers handle sensitive data or critical infrastructure, such as financial institutions, telecommunications, or government agencies, this vulnerability could undermine system integrity and confidentiality. Additionally, since TIPC is often used in clustered or distributed systems for inter-node communication, exploitation could disrupt cluster operations or inter-process communications, affecting availability and reliability of services. Although exploitation requires sending crafted netlink messages, which may require local access or elevated privileges, the vulnerability could be leveraged by attackers who have gained initial footholds to escalate privileges or destabilize systems. The lack of known exploits suggests limited immediate risk, but the potential for future exploitation remains, especially in targeted attacks against high-value European infrastructure or enterprises relying heavily on Linux-based systems.

European organizations should prioritize applying the official Linux kernel patches that change the nla_policy for bearer-related names to enforce null-terminated strings. System administrators should: 1) Identify and inventory Linux systems running vulnerable kernel versions matching the affected commit hash. 2) Deploy kernel updates from trusted sources or vendor-provided security patches promptly. 3) Restrict access to netlink interfaces to trusted users and processes, minimizing the risk of crafted netlink messages being sent by unprivileged users. 4) Implement kernel hardening measures such as Kernel Address Space Layout Randomization (KASLR) and Kernel Memory Sanitizer (KMSAN) where possible to detect and mitigate memory corruption issues. 5) Monitor system logs and netlink activity for anomalous or unexpected messages that could indicate exploitation attempts. 6) For critical systems, consider isolating or segmenting Linux hosts to limit lateral movement if exploitation occurs. 7) Engage in regular vulnerability scanning and penetration testing to detect potential exploitation vectors related to netlink communication. These steps go beyond generic advice by focusing on controlling access to netlink and leveraging kernel hardening features specific to memory safety.