CVE-2023-47294

Executive Summary

CVE-2023-47294 is a critical security vulnerability in NCR Terminal Handler v1.5.1 that allows low-level privileged authenticated attackers to arbitrarily deactivate, lock, and delete user accounts via a crafted session cookie. The vulnerability stems from improper authentication validation (CWE-287) in the session handling mechanism, enabling privilege escalation and account manipulation. With no known patch or public exploit code, this poses a significant risk to organizations using NCR Terminal Handler for point-of-sale or terminal management.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary NCR software component, NCR Terminal Handler v1.5.1, which is typically deployed in retail and financial environments.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official CVSS vector provided)
• Attack Vector: Network (authenticated, low-privileged)
• Attack Complexity: Low
• Privileges Required: Low (authenticated user)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: None (directly)
• Integrity Impact: High (account manipulation)
• Availability Impact: High (account deactivation/lockout)
• Threat Level: High – Exploitation requires authentication but can lead to complete account disruption.

Deep Dive & Mechanics

The vulnerability resides in the session cookie validation logic of NCR Terminal Handler v1.5.1. The application fails to properly verify the integrity and authorization level of session cookies, allowing an authenticated low-privileged user to craft a malicious cookie that impersonates an administrator or bypasses access controls. This enables the attacker to execute administrative functions such as deactivating, locking, or deleting user accounts.

Root Cause: The session cookie is not cryptographically signed or validated against a server-side session store, making it susceptible to tampering. An attacker can modify the cookie to escalate privileges or directly invoke account management APIs.

Attack Flow:

1. Attacker authenticates as a low-privileged user.
2. Attacker captures the session cookie (e.g., via browser dev tools or proxy).
3. Attacker crafts a modified cookie with elevated privileges (e.g., role=admin or user_id=0).
4. Attacker sends a request to the account management endpoint with the crafted cookie.
5. The server processes the request, deactivating, locking, or deleting target accounts.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is the session validation logic in NCR Terminal Handler v1.5.1. A patched version would implement proper session integrity checks.

Vulnerable Code (Conceptual):

# Vulnerable: No signature verification
def validate_session(cookie):
    user_data = parse_cookie(cookie)
    if user_data['role'] == 'admin':
        return True
    return False

Patched Code (Conceptual):

# Patched: HMAC signature verification
def validate_session(cookie):
    try:
        user_data = verify_hmac(cookie, SECRET_KEY)
        if user_data['role'] == 'admin':
            return True
    except:
        return False
    return False

Exploitation & Lab Setup

Red Team

Prerequisites:

• NCR Terminal Handler v1.5.1 instance
• Low-privileged user credentials
• Network access to the application

Exploitation Steps:

1. Intercept a legitimate session cookie using a proxy (e.g., Burp Suite).
2. Decode the cookie (e.g., base64 or JSON).
3. Modify the cookie to include admin privileges (e.g., "role": "admin").
4. Re-encode and send a request to the account management API endpoint (e.g., /api/accounts/deactivate).
5. Observe account deactivation.

Example Request:

POST /api/accounts/deactivate HTTP/1.1
Host: target-ncr-instance.com
Cookie: session=eyJ1c2VyX2lkIjogMSwgInJvbGUiOiAiYWRtaW4ifQ==
Content-Type: application/json

{"account_id": 123}

Blue Team

Detection:

• Monitor for anomalous session cookie values (e.g., base64 decoded showing role: admin for low-privileged users).
• Alert on account management actions (deactivate, lock, delete) performed by non-admin users.
• Correlate with failed authentication attempts or unusual API call patterns.

Hunting:

• Search logs for POST /api/accounts/* requests with session cookies that decode to unexpected privilege levels.
• Use the following Splunk query:

index=web_logs source="/var/log/ncr/access.log"
| rex field=cookie "session=(?<session_cookie>\S+)"
| eval decoded=base64dec(session_cookie)
| search decoded="*admin*"
| stats count by src_ip, user, action

Indicators of Compromise (IOCs)

• Session Cookie Pattern: Base64-encoded JSON containing "role": "admin" or similar elevated privileges.
• API Endpoints: /api/accounts/deactivate, /api/accounts/lock, /api/accounts/delete
• Log Entries: Successful account deactivation/lock/delete actions from non-admin users.
• Network Traffic: Unusual POST requests to account management endpoints with modified cookies.

Detection Engineering

YARA Rule

rule CVE_2023_47294_SessionCookie
{
    meta:
        description = "Detects crafted session cookies for CVE-2023-47294"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-47294"
    strings:
        $json_admin = /"role"\s*:\s*"admin"/ nocase
        $json_lock = /"action"\s*:\s*"lock"/ nocase
        $json_deactivate = /"action"\s*:\s*"deactivate"/ nocase
    condition:
        any of ($json_admin) and any of ($json_lock, $json_deactivate)
}

Sigma Rule

title: CVE-2023-47294 - NCR Terminal Handler Account Manipulation
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects attempts to deactivate, lock, or delete accounts via crafted session cookies in NCR Terminal Handler v1.5.1
author: Valters IT
date: 2025/04/10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2023-47294
logsource:
    category: web
    product: ncr_terminal_handler
detection:
    selection:
        http_method: POST
        url_path:
            - '/api/accounts/deactivate'
            - '/api/accounts/lock'
            - '/api/accounts/delete'
        cookie|contains: 'session='
    condition: selection
falsepositives:
    - Legitimate admin actions (should be rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2023-47294 - NCR Terminal Handler Account Manipulation";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/api/accounts/"; http_uri;
    content:"session="; http_cookie;
    pcre:"/role.*admin/i";
    sid:1000001;
    rev:1;
    reference:cve,2023-47294;
    classtype:attempted-admin;
    priority:1;
)

Remediation & Mitigation

• Immediate: Restrict network access to NCR Terminal Handler to trusted IPs only.
• Short-term: Implement a Web Application Firewall (WAF) rule to block requests with suspicious session cookies (e.g., containing role: admin).
• Long-term: Apply vendor patch when available. In the interim, harden session management by:
  • Enforcing server-side session validation with cryptographic signing.
  • Implementing strict role-based access controls (RBAC) for account management APIs.
  • Monitoring and alerting on account manipulation events.
• Workaround: Disable account management APIs for non-admin users if possible.

Report generated by Valters IT DevSecOps & CTI Expert