CVE-2024-6126 is a security vulnerability identified in the cockpit package, a web-based server management tool widely used on Linux systems. The flaw arises when the pam_env module's user_readenv option is enabled. This option allows users to read environment variables from a file, but due to improper control, an authenticated user can exploit this feature to kill arbitrary processes on the system. The attack vector requires the attacker to be authenticated with low privileges and to perform user interaction, such as triggering the environment variable reading process. The consequence is a denial of service (DoS) condition caused by uncontrolled resource consumption, where critical processes can be terminated, disrupting system availability. The vulnerability does not affect confidentiality or integrity, as it does not allow data leakage or unauthorized data modification. The CVSS v3.1 base score is 3.2, reflecting low severity due to limited impact and exploitation complexity. No public exploits have been reported yet, and no patches are currently linked, indicating that remediation may require vendor updates or configuration changes. This vulnerability highlights the risks of enabling certain pam_env options without strict controls, especially in multi-user environments.

For European organizations, the primary impact of CVE-2024-6126 is the potential for denial of service on systems running the cockpit package with pam_env's user_readenv enabled. This can lead to disruption of server management capabilities, affecting operational continuity, especially in environments relying on cockpit for remote administration and monitoring. Critical infrastructure sectors such as energy, telecommunications, and finance that use Linux servers with cockpit may experience temporary outages or degraded service. Although the vulnerability does not compromise data confidentiality or integrity, the loss of availability can hinder incident response, system updates, and routine management tasks. Organizations with strict uptime requirements or those operating in regulated industries may face compliance and operational risks. The absence of known exploits reduces immediate threat likelihood, but the ease of exploitation by authenticated users means insider threats or compromised credentials could be leveraged to trigger the DoS condition.

To mitigate CVE-2024-6126, organizations should first audit their use of the cockpit package and verify if the pam_env module's user_readenv option is enabled. Disabling the user_readenv option is the most direct and effective mitigation to prevent exploitation. If disabling is not feasible, restrict access to authenticated users with minimal privileges and monitor for unusual process terminations or resource consumption patterns. Implement strict access controls and multi-factor authentication to reduce the risk of credential compromise. Regularly update the cockpit package and related dependencies as vendors release patches addressing this vulnerability. Additionally, employ process monitoring and alerting tools to detect abnormal process kills that may indicate exploitation attempts. Conduct user training to raise awareness about the risks of environment variable manipulation and enforce least privilege principles for user accounts with cockpit access.