CVE-2024-54952 is a high-severity memory corruption vulnerability affecting the SMB service in MikroTik RouterOS version 6.40.5. The vulnerability arises from a null pointer dereference triggered by processing specially crafted packets sent by remote attackers. This flaw allows unauthenticated attackers to cause a Remote Denial of Service (DoS) condition by crashing or rendering the SMB service unavailable. The vulnerability is classified under CWE-476 (NULL Pointer Dereference), which typically leads to application crashes or service interruptions. Exploitation requires no authentication or user interaction and can be performed remotely over the network, making it relatively easy to exploit. The impact is limited to availability, with no direct compromise of confidentiality or integrity reported. Although no patches or fixes are currently linked, the vulnerability disclosure date is May 29, 2025, and no known exploits are reported in the wild at this time. The CVSS v3.1 base score is 7.5, reflecting the ease of exploitation and the high impact on service availability. MikroTik RouterOS is widely used in networking equipment, including routers and wireless devices, often deployed in enterprise, ISP, and critical infrastructure environments. The SMB service is commonly used for file sharing and network resource access, so disruption could affect network operations and availability of shared resources.

For European organizations, this vulnerability poses a significant risk to network stability and service availability, especially for those relying on MikroTik RouterOS devices for routing and SMB-based file sharing. A successful DoS attack could disrupt internal communications, access to shared files, and potentially impact business continuity. Critical sectors such as telecommunications, government, finance, and utilities that depend on stable network infrastructure could experience operational downtime. Given the unauthenticated nature of the exploit, attackers could launch attacks from external networks without prior access, increasing the threat surface. Although no data breach or integrity compromise is indicated, the loss of availability could indirectly affect productivity, incident response, and service-level agreements. Additionally, the lack of available patches means organizations must rely on mitigation and network-level controls until a fix is released.

1. Network Segmentation: Isolate MikroTik devices and SMB services from untrusted networks, restricting access to trusted hosts only. 2. Firewall Rules: Implement strict firewall policies to block or limit SMB traffic (typically TCP ports 445 and 139) from untrusted sources, especially over the internet. 3. Disable SMB Service: If SMB functionality on MikroTik devices is not required, disable the SMB service entirely to eliminate the attack vector. 4. Monitoring and Detection: Deploy network intrusion detection systems (NIDS) to monitor for anomalous SMB traffic patterns or malformed packets indicative of exploitation attempts. 5. Vendor Coordination: Engage with MikroTik support channels to obtain information on patches or firmware updates addressing this vulnerability and plan timely deployment once available. 6. Incident Response Preparedness: Prepare response plans for potential DoS incidents affecting SMB services, including fallback communication methods and rapid device reboot procedures. 7. Access Control: Limit administrative access to MikroTik devices and ensure strong authentication mechanisms are in place to prevent lateral movement if devices are compromised.