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1. EXECUTIVE SUMMARY

• CVSS v4 8.6
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: MicroDicom
• Equipment: DICOM Viewer
• Vulnerability: Out-of-bounds Write

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on affected installations of DICOM Viewer.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following MicroDicom products are affected:

• DICOM Viewer: Versions 2025.2 (Build 8154) and prior

3.2 VULNERABILITY OVERVIEW

3.2.1 OUT-OF-BOUNDS WRITE CWE-787

DICOM Viewer suffers from an out-of-bounds write vulnerability. Remote attackers are able to exploit this issue to potentially execute arbitrary code on affected installations of DICOM Viewer. User interaction is required to exploit the vulnerability in that the user must either visit a malicious website or open a malicious DICOM file locally.

CVE-2025-5943 has been assigned to this vulnerability. A CVSS v3.1 base score of 8.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

A CVSS v4 score has also been calculated for CVE-2025-5943. A base score of 8.6 has been calculated; the CVSS vector string is (AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Healthcare and Public Health
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Bulgaria

3.4 RESEARCHER

Michael Heinzl reported this vulnerability to CISA.

4. MITIGATIONS

MicroDicom recommends users update DICOM Viewer to version 2025.3 or later.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, such as:

• Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
• Locate control system networks and remote devices behind firewalls and isolating them from business networks.
• When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

• Do not click web links or open attachments in unsolicited email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.

5. UPDATE HISTORY

• June 10, 2025: Initial Publication