CVE-2025-5943 Overview
CVE-2025-5943 is an out-of-bounds write vulnerability affecting MicroDicom DICOM Viewer, a medical imaging application used to view and process DICOM (Digital Imaging and Communications in Medicine) files. Remote attackers can exploit this issue to potentially execute arbitrary code on affected installations. Successful exploitation requires user interaction—the victim must either visit a malicious website or open a specially crafted DICOM file locally.
Critical Impact
This out-of-bounds write vulnerability enables remote code execution in medical imaging software, potentially compromising healthcare workstations processing diagnostic images. The network-accessible attack vector combined with the high impact on confidentiality, integrity, and availability makes this a significant threat to healthcare environments.
Affected Products
- MicroDicom DICOM Viewer
Discovery Timeline
- June 10, 2025 - CVE-2025-5943 published to NVD
- June 12, 2025 - Last updated in NVD database
Technical Details for CVE-2025-5943
Vulnerability Analysis
This vulnerability is classified as CWE-787 (Out-of-Bounds Write), a memory corruption issue where the application writes data past the allocated buffer boundary. In the context of MicroDicom DICOM Viewer, the vulnerability occurs during the parsing or processing of DICOM image files. When a specially crafted DICOM file is processed, the application fails to properly validate buffer boundaries, allowing an attacker to overwrite adjacent memory regions.
The exploitation requires user interaction—either visiting a malicious website that triggers the vulnerability through the application's protocol handlers, or directly opening a malicious DICOM file. Once triggered, the out-of-bounds write can corrupt memory in a controlled manner, potentially allowing the attacker to redirect program execution and achieve arbitrary code execution.
Healthcare environments are particularly vulnerable because DICOM files are routinely exchanged between medical systems, imaging equipment, and diagnostic workstations, creating numerous opportunities for attackers to deliver malicious files.
Root Cause
The root cause is improper bounds checking during DICOM file parsing operations. The application fails to validate that write operations remain within the allocated buffer boundaries when processing certain malformed or malicious DICOM file structures. This allows attackers to craft DICOM files that trigger writes beyond the intended memory region.
Attack Vector
The attack is network-based but requires user interaction. An attacker can exploit this vulnerability through two primary vectors:
Malicious Website: An attacker hosts a malicious DICOM file on a website. When a user visits the site, the file may be processed by the DICOM Viewer if the application is registered as a handler for DICOM content types.
Malicious DICOM File: An attacker distributes a crafted DICOM file through email, file sharing, or by compromising a PACS (Picture Archiving and Communication System). When a user opens the file in MicroDicom DICOM Viewer, the out-of-bounds write is triggered.
Both attack vectors ultimately lead to memory corruption that can be leveraged for arbitrary code execution, giving the attacker control over the affected system.
The vulnerability manifests during DICOM file processing where buffer boundaries are not properly validated. See the CISA Medical Advisory ICSMA-25-160-01 for additional technical details.
Detection Methods for CVE-2025-5943
Indicators of Compromise
- Unexpected crashes or application hangs in MicroDicom DICOM Viewer when processing image files
- Suspicious DICOM files with anomalous file structures or unusually large embedded data segments
- Unusual process behavior from the DICOM Viewer application, such as spawning child processes or making network connections
- Memory access violations or exception events logged by system monitoring tools
Detection Strategies
- Deploy endpoint detection and response (EDR) solutions configured to monitor memory corruption exploitation attempts
- Implement application whitelisting to detect unauthorized code execution from the DICOM Viewer process
- Monitor for abnormal file access patterns involving DICOM files from untrusted sources
- Use memory integrity monitoring to detect heap and stack corruption attempts
Monitoring Recommendations
- Enable verbose logging for DICOM Viewer applications and centralize logs for security analysis
- Monitor network traffic for suspicious DICOM file downloads from untrusted external sources
- Implement file integrity monitoring on directories where DICOM files are stored
- Configure security tools to alert on exploitation techniques commonly used with out-of-bounds write vulnerabilities
How to Mitigate CVE-2025-5943
Immediate Actions Required
- Review the CISA Medical Advisory ICSMA-25-160-01 for vendor-specific remediation guidance
- Restrict DICOM file processing to files from trusted sources only
- Ensure endpoint protection solutions are updated with the latest detection signatures
- Isolate workstations running vulnerable versions of MicroDicom DICOM Viewer from direct internet access
- Educate users about the risks of opening DICOM files from unknown or untrusted sources
Patch Information
Refer to the CISA Medical Advisory ICSMA-25-160-01 for the latest patching guidance from MicroDicom. Organizations should check for updated versions of the DICOM Viewer that address this vulnerability and apply patches following their standard change management procedures.
Workarounds
- Implement network segmentation to isolate medical imaging workstations from general network traffic
- Configure web browser and email gateway filters to block or quarantine DICOM files from external sources
- Use a sandboxed environment for opening DICOM files from untrusted sources
- Disable automatic protocol handler registration for the DICOM Viewer application to prevent drive-by exploitation
# Example: Restrict DICOM file access permissions on Windows (run as Administrator)
# Limit write access to DICOM directories to authorized users only
icacls "C:\DICOM\Import" /inheritance:r /grant "SYSTEM:(OI)(CI)F" /grant "Administrators:(OI)(CI)F" /grant "DICOMUsers:(OI)(CI)RX"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
