CVE-2024-4056 is a vulnerability identified in M-Files Server, a document management system widely used in enterprise environments. The root cause is inefficient regular expression complexity (CWE-1333) within the server's processing logic. This inefficiency can be exploited by an unauthenticated remote attacker to trigger excessive CPU or memory consumption, leading to a denial of service (DoS) condition. The affected versions include those before 24.4.13592.4 and after 23.11, excluding the 24.2 LTS release. The vulnerability requires no authentication or user interaction, making it accessible to any remote attacker who can reach the server. While the vulnerability does not compromise data confidentiality or integrity, it can severely impact availability by causing the server to become unresponsive or crash under load. No public exploits have been reported yet, but the vulnerability's nature and ease of exploitation make it a critical concern for organizations relying on M-Files Server for document management and collaboration. The CVSS 3.1 score of 7.5 reflects a high severity level, primarily due to the network attack vector, low attack complexity, and the lack of required privileges or user interaction.

The primary impact of CVE-2024-4056 is on the availability of M-Files Server, potentially causing service outages or degraded performance due to resource exhaustion. Organizations relying on M-Files for document management, workflow automation, and collaboration may experience disruptions, affecting business continuity and productivity. In environments where M-Files Server supports critical operations, such as legal, financial, or healthcare sectors, this DoS vulnerability could lead to operational delays and increased risk of non-compliance with regulatory requirements. Since the vulnerability is exploitable without authentication, attackers can launch DoS attacks at scale, potentially affecting multiple organizations simultaneously. Although no data breach or integrity compromise is involved, the denial of service can indirectly impact trust and operational reliability. The lack of known exploits in the wild currently reduces immediate risk, but the vulnerability's characteristics suggest it could be targeted in the future.

Organizations should monitor M-Files Corporation advisories and apply patches or updates as soon as they become available, specifically upgrading to versions 24.4.13592.4 or later, or the 24.2 LTS release which is not affected. Until patches are released, network-level mitigations such as implementing rate limiting, web application firewalls (WAFs), or intrusion prevention systems (IPS) to detect and block suspicious requests targeting the vulnerable regular expressions can reduce exposure. Restricting access to M-Files Server interfaces to trusted IP ranges and using VPNs or zero-trust network access can limit attack surface. Additionally, configuring resource limits on the server to prevent excessive CPU or memory usage by individual processes may help contain the impact of exploitation attempts. Regular monitoring of server performance and logs for unusual spikes in resource consumption or traffic patterns is recommended to detect potential exploitation attempts early. Finally, organizations should review and harden their overall network segmentation and incident response plans to quickly isolate affected systems if an attack occurs.