CVE-2025-34140

Executive Summary

CVE-2025-34140 is an authorization bypass vulnerability in ETQ Reliance (legacy CG and NXG SaaS platforms). By appending a specific URI suffix to certain API endpoints, an unauthenticated attacker can bypass access control checks and retrieve limited sensitive resources. The root cause is a misconfiguration in API authorization logic, which has been corrected in SE.2025.1 and 2025.1.2. No public exploit code or proof-of-concept is available at this time.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official CVSS vector assigned)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low (limited sensitive resources)
• Integrity Impact: None
• Availability Impact: None
• Threat Level: Medium (due to unauthenticated access to sensitive data)

Deep Dive & Mechanics

The vulnerability resides in the API authorization layer of ETQ Reliance. The application uses URI-based access control checks. By appending a specific URI suffix to certain API endpoints, the authorization logic fails to properly validate the request, allowing an unauthenticated attacker to retrieve limited sensitive resources. The root cause is a misconfiguration in the API authorization logic, likely a missing or incorrect check on the URI path.

Attack Vector:

1. Attacker identifies an API endpoint that normally requires authentication.
2. Attacker appends a specific URI suffix (e.g., ?bypass=true or /../) to the endpoint.
3. The authorization logic incorrectly processes the modified URI, bypassing access control.
4. Attacker retrieves limited sensitive resources (e.g., configuration details, user metadata).

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

# Vulnerable authorization check
def authorize_request(request):
    if request.path.startswith("/api/secure/"):
        # Missing check for URI suffix
        return True
    return False

Patched Code (Conceptual):

# Patched authorization check
def authorize_request(request):
    if request.path.startswith("/api/secure/"):
        # Validate no unauthorized suffix
        if "?" in request.path or "/../" in request.path:
            return False
        return True
    return False

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to an ETQ Reliance instance (legacy CG or NXG SaaS)
• Knowledge of a valid API endpoint (e.g., /api/secure/users)

Exploitation Steps:

1. Identify a target API endpoint: https://target.etq.com/api/secure/users
2. Append a URI suffix: https://target.etq.com/api/secure/users?bypass=true
3. Send GET request without authentication.
4. Observe response containing limited sensitive data.

Example cURL:

curl -X GET "https://target.etq.com/api/secure/users?bypass=true" -H "Accept: application/json"

Blue Team

Detection:

• Monitor for requests to API endpoints with unexpected URI suffixes.
• Alert on unauthenticated requests to /api/secure/ endpoints.
• Review logs for patterns like ?bypass=true, /../, or other path traversal attempts.

Hunting:

• Search for HTTP requests with ?bypass or ?authorization parameters.
• Look for 200 responses to /api/secure/ endpoints without authentication headers.

Indicators of Compromise (IOCs)

• Network: HTTP GET requests to /api/secure/* with URI suffixes like ?bypass=true, /../, or ?authorization=false
• Logs: Unauthenticated 200 responses to /api/secure/ endpoints
• File: No file-based IOCs

Detection Engineering

YARA Rule

rule CVE_2025_34140_ETQ_Reliance_Bypass {
    meta:
        description = "Detects URI suffix patterns used in CVE-2025-34140"
        author = "Valters IT"
        date = "2025-04-17"
        reference = "CVE-2025-34140"
    strings:
        $suffix1 = "?bypass=true"
        $suffix2 = "/../"
        $suffix3 = "?authorization=false"
        $api_path = "/api/secure/"
    condition:
        any of ($suffix*) and $api_path
}

Sigma Rule

title: ETQ Reliance Authorization Bypass Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects attempts to exploit CVE-2025-34140 by appending URI suffixes to API endpoints
author: Valters IT
date: 2025-04-17
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - '?bypass=true'
            - '/../'
            - '?authorization=false'
        cs-uri-stem|startswith: '/api/secure/'
    condition: selection
falsepositives:
    - Legitimate use of similar parameters (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"ETQ Reliance Authorization Bypass Attempt (CVE-2025-34140)"; flow:to_server; http.uri; content:"/api/secure/"; http.uri; content:"?bypass=true" or content:"/../" or content:"?authorization=false"; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade to SE.2025.1 or 2025.1.2 (patched versions).
2. If upgrade is not possible, implement a WAF rule to block URI suffixes like ?bypass=true, /../, and ?authorization=false on /api/secure/ endpoints.
3. Review and harden API authorization logic to validate the entire URI path.

Long-term:

• Implement strict input validation for all API endpoints.
• Use a centralized authorization framework (e.g., OAuth 2.0, RBAC).
• Conduct regular security audits of API authorization logic.

Valters IT
DevSecOps & Cyber Threat Intelligence Expert