CVE-2025-62416

Executive Summary

CVE-2025-62416 is a Server-Side Template Injection (SSTI) vulnerability in Bagisto v2.3.7, an open-source Laravel eCommerce platform. The flaw arises from unsanitized user input being processed by the server-side templating engine when rendering product descriptions. An attacker with product creation privileges can inject arbitrary template expressions, leading to Remote Code Execution (RCE) on the server. The vulnerability is fixed in version 2.3.8.

CVSS Breakdown & Threat Level

• CVSS Score: 5.1 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: High (PR:H) – requires product creation privileges
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: High (A:H)

The threat level is elevated due to the potential for RCE, though the requirement for authenticated access with product creation privileges reduces the attack surface.

Deep Dive & Mechanics

The vulnerability exists in the product description rendering functionality. Bagisto uses a server-side templating engine (likely Blade or Twig) to render product descriptions. When a user with product creation privileges submits a product description, the input is not sanitized before being passed to the templating engine. This allows an attacker to inject template expressions such as {{7*7}} or {{system('id')}} which are evaluated on the server.

The injection point is in the product description field during product creation or editing. The templating engine processes the input without escaping, leading to SSTI. Successful exploitation can result in arbitrary code execution, data exfiltration, or full server compromise.

Vulnerable vs. Patched Code

Vulnerable Code (v2.3.7):

// In ProductController or similar
$product->description = $request->input('description');
$product->save();
// Later, when rendering:
return view('product.show', ['product' => $product]);
// In the Blade template:
{!! $product->description !!}

Patched Code (v2.3.8):

// Sanitize input before saving
$product->description = strip_tags($request->input('description'));
// Or use Blade's {{ }} syntax instead of {!! !!}
// In the Blade template:
{{ $product->description }}

The patch ensures that user input is sanitized (e.g., using strip_tags() or htmlspecialchars()) and that the output is escaped using Blade's {{ }} syntax instead of the raw {!! !!} syntax.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to a Bagisto v2.3.7 instance with product creation privileges.
• Basic understanding of SSTI payloads.

Exploitation Steps:

1. Log in as a user with product creation privileges.
2. Navigate to the product creation/editing page.
3. In the product description field, inject an SSTI payload. For example:

   {{7*7}}
   

   If the output shows 49, SSTI is confirmed.
4. Escalate to RCE using a payload like:

   {{system('id')}}
   

   Or for Laravel Blade:

   {!! system('id') !!}
   

5. Execute arbitrary commands to achieve full server compromise.

Lab Setup:

• Deploy Bagisto v2.3.7 using Docker:

  docker run -d -p 80:80 bagisto/bagisto:2.3.7
  

• Create a user with product creation privileges.
• Use a tool like Burp Suite or curl to craft requests.

Blue Team

Detection:

• Monitor for unusual template expressions in product descriptions (e.g., {{, {!!, {%).
• Look for unexpected system commands in web server logs.
• Use WAF rules to block SSTI payloads.

Hunting:

• Search for product descriptions containing template syntax.
• Review access logs for POST requests to product creation endpoints with suspicious payloads.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /admin/products or /products with payloads containing {{, {!!, or {%.
• File System: Unexpected files in the web root (e.g., shell.php, cmd.php).
• Process: Unusual processes spawned by the web server user (e.g., id, whoami, cat /etc/passwd).
• Logs: Web server logs showing system('id') or similar commands in the request body.

Detection Engineering

YARA Rule

rule CVE_2025_62416_SSTI_Payload {
    meta:
        description = "Detects SSTI payloads targeting Bagisto CVE-2025-62416"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-62416"
    strings:
        $ssti1 = "{{" ascii wide
        $ssti2 = "{!!" ascii wide
        $ssti3 = "{%" ascii wide
        $cmd1 = "system(" ascii wide
        $cmd2 = "exec(" ascii wide
        $cmd3 = "shell_exec(" ascii wide
    condition:
        any of ($ssti*) and any of ($cmd*)
}

Sigma Rule

title: CVE-2025-62416 SSTI Exploitation Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects SSTI payloads in HTTP requests to Bagisto product endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains:
            - '/admin/products'
            - '/products'
        cs-body|contains:
            - '{{'
            - '{!!'
            - '{%'
    condition: selection
falsepositives:
    - Legitimate use of template syntax in product descriptions (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-62416 SSTI Exploitation Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/admin/products" or content:"/products"; http_uri; content:"{{" or content:"{!!" or content:"{%"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate:

• Upgrade Bagisto to version 2.3.8 or later.
• If upgrade is not possible, apply input sanitization to product descriptions (e.g., strip_tags(), htmlspecialchars()).
• Use Blade's {{ }} syntax instead of {!! !!} for rendering user input.

Long-term:

• Implement a Web Application Firewall (WAF) with SSTI detection rules.
• Conduct regular security audits of custom code.
• Follow secure coding practices, including input validation and output escaping.

Workaround:

• Disable product creation for untrusted users.
• Manually review all product descriptions before publishing.

Valters IT