CVE-2022-23950 is a security vulnerability identified in the Keylime software prior to version 6.3.0. Keylime is an open-source project designed to provide remote attestation and integrity measurement for cloud and edge computing environments, ensuring that systems are running trusted software. The vulnerability is classified under CWE-379, which relates to the use of a predictable or fixed resource, in this case, a UNIX domain socket path. Specifically, the Revocation Notifier component of Keylime uses a fixed path under /tmp for its UNIX domain socket. This predictable socket location allows unprivileged local users to interfere with Keylime operations by creating or manipulating the socket file, effectively causing a denial of service (DoS). Since the socket is used for inter-process communication, an attacker can block or disrupt communication by pre-creating the socket or otherwise manipulating it, preventing Keylime from functioning correctly. The vulnerability does not allow for confidentiality or integrity compromise of data but impacts availability by prohibiting Keylime operations. The CVSS v3.1 score is 7.5 (high severity), reflecting the network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality or integrity impact (C:N/I:N), but high impact on availability (A:H). No known exploits in the wild have been reported. The vulnerability was published on September 21, 2022, and affects versions before Keylime 6.3.0, which presumably addresses this issue by changing the socket path handling to a more secure method, such as using randomized or user-specific paths or appropriate permissions to prevent unauthorized interference.

For European organizations deploying Keylime in their cloud or edge infrastructure, this vulnerability poses a significant risk to the availability of their remote attestation and integrity verification processes. Keylime is often used in environments requiring high trust and security assurance, such as government agencies, critical infrastructure providers, and enterprises with sensitive data. Disruption of Keylime operations could lead to a loss of confidence in system integrity monitoring, potentially allowing compromised or untrusted systems to operate undetected. This could indirectly increase the risk of further attacks or data breaches. Moreover, denial of service conditions could impact operational continuity, especially in automated or large-scale deployments relying on Keylime for security enforcement. Since the vulnerability can be exploited by any local unprivileged user, insider threats or attackers who have gained limited access could leverage this to disrupt security controls. Although confidentiality and integrity are not directly impacted, the availability impact is critical in security-sensitive contexts. European organizations subject to strict regulatory requirements around system integrity and availability, such as those under NIS2 Directive or GDPR (where availability is a component of data protection), may face compliance and operational challenges if this vulnerability is exploited.

To mitigate CVE-2022-23950, European organizations should upgrade Keylime to version 6.3.0 or later, where the vulnerability has been addressed. If immediate upgrading is not feasible, organizations should implement the following specific mitigations: 1) Restrict access to the /tmp directory or the specific socket path by adjusting filesystem permissions and using mount options like 'noexec' or 'nodev' where appropriate to limit unprivileged user interference. 2) Employ mandatory access controls (e.g., SELinux, AppArmor) to confine Keylime processes and prevent unauthorized socket creation or manipulation. 3) Monitor the /tmp directory for unexpected socket files or changes, using file integrity monitoring tools to detect potential exploitation attempts. 4) Consider running Keylime components under dedicated service accounts with minimal privileges and isolated runtime environments to reduce the attack surface. 5) If possible, configure Keylime to use alternative socket paths outside of /tmp or use randomized socket names to avoid predictable resource conflicts. 6) Educate system administrators about the risk and ensure that local user accounts are tightly controlled and monitored to reduce the risk of insider threats exploiting this vulnerability. These targeted mitigations go beyond generic advice by focusing on filesystem permissions, process confinement, and monitoring specific to the nature of the vulnerability.