CVE-2025-3481 is a critical stack-based buffer overflow vulnerability found in MedDream PACS Server, specifically version 7.3.3.840 of MedDream PACS Premium. The vulnerability arises from improper validation of the length of user-supplied data during the parsing of DICOM files, which are standard medical imaging files used in Picture Archiving and Communication Systems (PACS). The flaw allows an attacker to overflow a fixed-length stack buffer by supplying maliciously crafted DICOM files. This buffer overflow can lead to remote code execution (RCE) without requiring any authentication or user interaction. The attacker can execute arbitrary code with the privileges of the service account running the PACS server, potentially compromising the confidentiality, integrity, and availability of the medical imaging system. The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow) and has a CVSS v3.0 score of 9.8, indicating a critical severity level. Although no public exploits have been reported yet, the ease of exploitation combined with the lack of authentication requirement makes this a highly dangerous vulnerability. The PACS server is a critical component in healthcare environments, responsible for storing and managing sensitive medical images and patient data, making this vulnerability particularly impactful in healthcare settings.

For European organizations, especially healthcare providers and hospitals, this vulnerability poses a severe risk. Exploitation could lead to unauthorized access to sensitive patient medical images and data, violating privacy regulations such as GDPR. The ability to execute arbitrary code remotely could allow attackers to disrupt medical imaging services, potentially delaying diagnoses and treatments. Furthermore, attackers could use the compromised PACS server as a foothold to move laterally within hospital networks, targeting other critical systems. The integrity of medical images could be compromised, leading to misdiagnosis or incorrect treatment plans. Given the critical nature of healthcare infrastructure in Europe and the strict regulatory environment, the impact extends beyond technical damage to legal and reputational consequences. Additionally, disruption of PACS services can have life-threatening implications, increasing the urgency for mitigation.

1. Immediate patching: Organizations should prioritize updating MedDream PACS Server to a patched version once available. Since no patch links are currently provided, contacting the vendor for an official fix or workaround is essential. 2. Network segmentation: Isolate PACS servers within dedicated network segments with strict access controls to limit exposure to untrusted networks. 3. Input validation: Implement additional filtering or validation of DICOM files at network gateways or proxy layers to detect and block malformed files. 4. Monitoring and detection: Deploy intrusion detection/prevention systems (IDS/IPS) with signatures for buffer overflow attempts targeting DICOM parsing. Monitor logs for unusual activity or crashes related to the PACS server. 5. Access controls: Restrict network access to the PACS server to only trusted systems and personnel. 6. Incident response readiness: Prepare for potential exploitation by having incident response plans tailored to PACS server compromise scenarios. 7. Vendor engagement: Engage with MedDream for timely updates and security advisories. 8. Backup and recovery: Maintain regular backups of PACS data and configurations to enable recovery in case of compromise.