CVE-2025-62650

Executive Summary

CVE-2025-62650 exposes a critical authentication bypass vulnerability in the Restaurant Brands International (RBI) assistant platform, affecting all versions through 2025-09-06. The platform relies solely on client-side authentication for access to its diagnostic screen, allowing any unauthenticated attacker to bypass security controls and gain privileged access. With a CVSS score of 8.3, this flaw enables remote attackers to view sensitive system diagnostics, modify configurations, or disrupt operations without any credentials. No patch has been confirmed, and no public exploit code exists at this time, but the attack surface is significant due to the lack of server-side enforcement.

CVSS Breakdown & Threat Level

• CVSS Score: 8.3 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• 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: None (UI:N) – no user action required.
• Scope: Unchanged (S:U) – vulnerability does not affect other components.
• Confidentiality Impact: High (C:H) – diagnostic data exposed.
• Integrity Impact: High (I:H) – diagnostic screen may allow configuration changes.
• Availability Impact: High (A:H) – potential to disrupt platform operations.

Threat Level: Critical due to the trivial exploitation vector and high potential impact on RBI’s global restaurant operations.

Deep Dive & Mechanics

The RBI assistant platform is a web-based tool used for managing restaurant operations, including diagnostics, monitoring, and configuration. The vulnerability lies in the diagnostic screen endpoint, which performs authentication checks entirely on the client side (e.g., via JavaScript or hidden HTML elements). An attacker can bypass this by directly requesting the diagnostic screen URL, manipulating client-side parameters, or disabling JavaScript to circumvent the authentication logic.

Root Cause: The server does not validate session tokens or credentials before serving the diagnostic screen content. Instead, the client-side code checks for a local flag (e.g., a cookie, local storage item, or URL parameter) and hides/shows the diagnostic interface accordingly. This design flaw allows any HTTP request to the diagnostic endpoint to return sensitive data.

Attack Flow:

1. Identify the diagnostic screen URL (e.g., /diagnostic, /admin/diag, /api/diagnostics).
2. Send a direct HTTP GET request to that endpoint without any authentication headers.
3. The server responds with the diagnostic interface HTML or JSON data, as it trusts the client to enforce access control.
4. Extract sensitive information such as system logs, network configurations, API keys, or internal IP addresses.

Potential Impact:

• Exposure of internal network topology and system health data.
• Leakage of API tokens or credentials embedded in diagnostic outputs.
• Ability to trigger diagnostic actions (e.g., restart services, clear caches) if the screen includes functional buttons.
• Further lateral movement within RBI’s infrastructure.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is described generically.

Vulnerable Code (Client-Side Authentication):

// Client-side check only
if (localStorage.getItem('isAdmin') === 'true') {
    document.getElementById('diagnosticScreen').style.display = 'block';
} else {
    document.getElementById('diagnosticScreen').style.display = 'none';
}

Patched Code (Server-Side Authentication):

# Server-side session validation
@app.route('/diagnostic')
def diagnostic():
    if not session.get('authenticated') or session.get('role') != 'admin':
        abort(403)
    return render_template('diagnostic.html')

Key Difference: The patched version validates the user’s session on the server before returning any sensitive data, preventing direct access to the diagnostic screen.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Environment:

• Target: RBI assistant platform instance (version through 2025-09-06)
• Attacker: Kali Linux with curl, Burp Suite, or browser developer tools

Exploitation Steps:

1. Reconnaissance: Use Shodan or Google dorks to find exposed RBI assistant platforms (e.g., inurl:/diagnostic or title:"RBI Assistant").
2. Direct Access: Send a simple HTTP request to the diagnostic endpoint:

   curl -v http://target.com/diagnostic
   

3. Bypass Client-Side Checks: If the endpoint returns a login page, inspect the HTML for hidden parameters or JavaScript that controls access. For example, add a query parameter:

   curl -v "http://target.com/diagnostic?auth=true"
   

4. Extract Data: Parse the response for sensitive information such as:
   • System logs
   • Database connection strings
   • API keys
   • Internal IP addresses
5. Automate: Use a script to enumerate all diagnostic endpoints:

   for endpoint in /diagnostic /admin/diag /api/diagnostics /status; do
       curl -s -o /dev/null -w "%{http_code}" http://target.com$endpoint
   done
   

Expected Outcome: Full access to the diagnostic screen without authentication, revealing sensitive operational data.

Blue Team (Defensive)

Detection & Response:

1. Monitor for Direct Endpoint Access: Alert on HTTP requests to /diagnostic, /admin/diag, or similar paths without prior authentication.
2. Analyze Logs: Look for 200 responses to diagnostic endpoints from IPs not in the admin allowlist.
3. Honeypot: Deploy a fake diagnostic endpoint that logs attacker behavior and triggers alerts.
4. Network Segmentation: Ensure the diagnostic screen is only accessible from internal management networks, not the public internet.
5. Immediate Mitigation: If possible, add a reverse proxy rule to block access to diagnostic endpoints unless authenticated:

   location /diagnostic {
       deny all;
       return 403;
   }
   

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests to /diagnostic, /admin/diag, /api/diagnostics from external IPs.
  • Unusual spikes in 200 responses to these endpoints.
  • User-Agent strings indicating automated scanning (e.g., curl, python-requests).

• File IOCs:

  • Access logs showing repeated attempts to diagnostic endpoints.
  • Temporary files created by attackers (e.g., /tmp/exploit.sh).

• Behavioral IOCs:

  • Multiple failed authentication attempts followed by a successful direct access to diagnostic screen.
  • Unauthorized changes to system configurations via diagnostic actions.

Detection Engineering

YARA Rule

rule CVE_2025_62650_RBI_Diagnostic_Bypass {
    meta:
        description = "Detects client-side authentication bypass in RBI assistant platform diagnostic screen"
        author = "Valters IT"
        date = "2025-09-06"
        reference = "CVE-2025-62650"
    strings:
        $s1 = "diagnostic" nocase
        $s2 = "localStorage" nocase
        $s3 = "isAdmin" nocase
        $s4 = "display = 'block'" nocase
    condition:
        any of ($s1, $s2, $s3, $s4)
}

Sigma Rule

title: CVE-2025-62650 - RBI Assistant Diagnostic Screen Access
id: 8a3f7c2e-1d4b-4f6a-9c8e-5b2a1d3f7c8e
status: experimental
description: Detects direct access to RBI assistant diagnostic endpoints without prior authentication
author: Valters IT
date: 2025-09-06
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-stem:
            - '/diagnostic'
            - '/admin/diag'
            - '/api/diagnostics'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin access from internal IPs
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-62650 - RBI Diagnostic Screen Access Attempt"; flow:to_server; content:"GET"; http_method; content:"/diagnostic"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Implement Server-Side Authentication: Add session validation on the server for all diagnostic endpoints. Reject requests without valid admin credentials.
2. Restrict Network Access: Use firewall rules or reverse proxy to limit diagnostic screen access to trusted IP ranges only.
3. Disable Diagnostic Screen: If not essential, remove or disable the diagnostic screen entirely until a patch is available.
4. Monitor Logs: Actively monitor for unauthorized access attempts to diagnostic endpoints.

Long-Term Fix:

• Vendor must release a patch that moves all authentication logic to the server side.
• Conduct a security audit of all client-side authentication mechanisms in the platform.
• Implement role-based access control (RBAC) for all administrative functions.

Workaround:

• Add a web application firewall (WAF) rule to block requests to diagnostic endpoints unless they include a valid session cookie:

  location /diagnostic {
      if ($cookie_session !~ "^valid_admin_session") {
          return 403;
      }
  }
  

Valters IT
Securing Digital Frontiers