CVE-2023-3108 is a vulnerability identified in the Linux kernel component of Red Hat Enterprise Linux 6, specifically within the cryptographic subsystem handling symmetric key cipher algorithms. The flaw resides in the get_user_pages_fast function used by the skcipher_recvmsg function in the crypto/algif_skcipher.c source file. This function is responsible for managing memory pages during cryptographic operations. The vulnerability allows a local user to trigger a race condition or resource exhaustion scenario (as indicated by CWE-362 and CWE-400) that leads to a system crash, effectively causing a denial of service (DoS). The vulnerability does not require elevated privileges (PR:N) or user interaction (UI:N), but it does require local access (AV:L). The impact is limited to availability, with no direct compromise of confidentiality or integrity. No known exploits have been reported in the wild, and no official patches have been linked at the time of publication. The CVSS v3.1 base score is 6.2, categorizing it as medium severity. This vulnerability is particularly relevant for organizations still operating Red Hat Enterprise Linux 6, which is an older, legacy operating system version that may not receive frequent updates. The flaw highlights risks in kernel-level cryptographic operations and the importance of maintaining updated kernel versions or migrating to supported OS releases.

For European organizations, the primary impact of CVE-2023-3108 is the potential for local users to cause system crashes, resulting in denial of service. This can disrupt critical services, especially in environments relying on Red Hat Enterprise Linux 6 for legacy applications or infrastructure. While the vulnerability does not allow data theft or modification, the loss of availability can affect business continuity, operational efficiency, and service-level agreements. Industries such as finance, manufacturing, telecommunications, and government agencies that depend on stable Linux-based systems may experience interruptions. Additionally, organizations with multi-user environments or shared hosting could face increased risk if untrusted local users exist. The lack of known exploits reduces immediate risk, but the presence of this vulnerability in older OS versions means that unpatched systems remain vulnerable to potential future exploitation. The impact is compounded by the fact that RHEL 6 is nearing or past its end-of-life, limiting vendor support and patch availability.

To mitigate CVE-2023-3108, European organizations should: 1) Restrict local user access to trusted personnel only, minimizing the risk of exploitation by unprivileged users. 2) Monitor Red Hat and Linux kernel security advisories closely for patches or updates addressing this vulnerability and apply them promptly once available. 3) Consider upgrading from Red Hat Enterprise Linux 6 to a more recent, supported version of the OS to benefit from ongoing security updates and improved kernel security. 4) Implement system hardening measures such as SELinux or AppArmor policies to limit the capabilities of local users and contain potential exploitation attempts. 5) Use monitoring and intrusion detection systems to detect unusual system crashes or kernel panics that may indicate exploitation attempts. 6) Conduct regular audits of user permissions and access controls to ensure no unauthorized local accounts exist. 7) For critical systems where immediate upgrade is not feasible, consider isolating affected systems from less trusted users or networks to reduce exposure.