CVE-2023-2006 is a high-severity vulnerability identified in the Linux kernel's RxRPC network protocol implementation. The root cause is a race condition (CWE-362) that arises due to improper locking mechanisms when handling RxRPC bundles. RxRPC (Remote Execution RPC) is a network protocol used primarily in distributed systems and certain enterprise environments, including some implementations of AFS (Andrew File System). The race condition allows concurrent operations on shared kernel objects without adequate synchronization, potentially leading to use-after-free or similar memory corruption scenarios. An attacker exploiting this flaw can escalate privileges by executing arbitrary code within the kernel context, effectively gaining full control over the affected system. The vulnerability requires local access (attack vector: AV:L) with low privileges (PR:L) but no user interaction (UI:N). The complexity of exploitation is high (AC:H), indicating that a skilled attacker with local access could trigger the race condition. The vulnerability affects Linux kernel versions prior to 6.1-rc7, where the issue has been fixed. No known exploits have been reported in the wild to date. The CVSS v3.1 base score is 7.0, reflecting high impact on confidentiality, integrity, and availability due to kernel-level code execution. This vulnerability is particularly critical in environments where the Linux kernel is used with RxRPC enabled and where untrusted users have local access, such as multi-user systems, shared hosting, or containerized environments with privileged access to the kernel. Since the flaw resides in kernel-level code, successful exploitation could compromise entire systems, bypassing most security controls and sandboxing mechanisms.

For European organizations, the impact of CVE-2023-2006 can be significant, especially in sectors relying heavily on Linux-based infrastructure such as telecommunications, cloud service providers, research institutions, and enterprises using AFS or RxRPC-enabled services. A successful exploit could lead to full system compromise, data breaches, service disruptions, and lateral movement within networks. This is particularly concerning for critical infrastructure and government agencies where Linux servers are prevalent. The vulnerability's requirement for local access limits remote exploitation but does not eliminate risk in environments where attackers may gain footholds via phishing, insider threats, or compromised credentials. Additionally, containerized environments or virtualized setups that share the kernel could be at risk if isolation boundaries are weak. The lack of known exploits in the wild suggests limited immediate threat, but the high impact and availability of a fix necessitate prompt patching to prevent future exploitation. European organizations with compliance obligations under GDPR and other data protection regulations must consider the risk of data exposure and operational impact due to this vulnerability.

Apply the Linux kernel update to version 6.1-rc7 or later where the race condition in the RxRPC protocol is fixed. Prioritize patching on all systems running affected kernel versions. Audit and restrict local user access to systems running vulnerable kernels, minimizing the number of users with shell or local login capabilities. Disable the RxRPC protocol if it is not required in your environment by recompiling the kernel without RxRPC support or disabling the module to reduce the attack surface. Implement strict access controls and monitoring on systems with RxRPC enabled to detect unusual local activity that could indicate exploitation attempts. Use kernel security modules such as SELinux or AppArmor to enforce mandatory access controls that may limit the impact of kernel-level exploits. In containerized or virtualized environments, ensure strong isolation and avoid granting privileged access to containers or users that could trigger local exploits. Regularly review and update incident response plans to include scenarios involving kernel-level compromises and ensure backups and recovery procedures are robust.