CVE-2015-10138 – The Work The Flow File Upload WordPress plugin ... (How to Fix)

Q: What is the severity of CVE-2015-10138?

CVE-2015-10138 has a CVSS score of 9.8 (CRITICAL). The Work The Flow File Upload WordPress plugin has an unauthenticated arbitrary file upload vulnerability due to missing file type validation. This allows attackers to upload malicious files to affected WordPress sites, potentially leading to remote code execution. All WordPress sites using vulnerable plugin versions are affected.

📋 TL;DR

The Work The Flow File Upload WordPress plugin has an unauthenticated arbitrary file upload vulnerability due to missing file type validation. This allows attackers to upload malicious files to affected WordPress sites, potentially leading to remote code execution. All WordPress sites using vulnerable plugin versions are affected.

💻 Affected Systems

Products:

Work The Flow File Upload WordPress plugin

Versions: Up to and including version 2.5.2

Operating Systems: All

Default Config Vulnerable: ⚠️ Yes

Notes: Affects WordPress sites with the vulnerable plugin installed and activated.

📦 What is this software?

Work The Flow File Upload by Lynton Reed

View all CVEs affecting Work The Flow File Upload →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete server compromise via remote code execution, allowing attackers to install backdoors, steal data, deface websites, or use the server for further attacks.

🟠

Likely Case

Website defacement, malware distribution, credential theft, or use as part of a botnet.

🟢

If Mitigated

Limited impact if file uploads are restricted by web application firewall or server-side controls.

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: CONFIRMED

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploit code is publicly available and requires minimal technical skill to execute.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Version 2.5.3 or later

Vendor Advisory: https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=1127456%40work-the-flow-file-upload&new=1127456%40work-the-flow-file-upload&sfp_email=&sfph_mail=

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'Work The Flow File Upload' and update to version 2.5.3 or later. 4. Alternatively, disable and remove the plugin if not needed.

🔧 Temporary Workarounds

Disable plugin

all

Temporarily disable the vulnerable plugin until patching is possible.

wp plugin deactivate work-the-flow-file-upload

Restrict file uploads via .htaccess

linux

Block uploads to the vulnerable endpoint using web server configuration.

<FilesMatch "\.(php|phtml|php3|php4|php5|php7|phps|php8|inc|pl|py|jsp|asp|aspx|sh|cgi|exe|dll|bat|cmd|ps1|psm1|psd1|vbs|vbe|js|jse|wsf|wsh|msc|jar|war|ear|rb|action|swf|html|htm|svg|xml)">\n    Order Allow,Deny\n    Deny from all\n</FilesMatch>

🧯 If You Can't Patch

Implement web application firewall rules to block malicious file uploads
Restrict file permissions on upload directories to prevent execution

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin panel → Plugins → Installed Plugins for 'Work The Flow File Upload' version 2.5.2 or earlier.

Check Version:

wp plugin list --name=work-the-flow-file-upload --field=version

Verify Fix Applied:

Confirm plugin version is 2.5.3 or later in WordPress admin panel.

📡 Detection & Monitoring

Log Indicators:

Unusual file uploads to /wp-content/plugins/work-the-flow-file-upload/
POST requests to upload.php with suspicious file extensions
Multiple failed upload attempts

Network Indicators:

HTTP POST requests to plugin upload endpoints with executable file types
Unusual outbound connections from web server after uploads

SIEM Query:

source="web_server_logs" AND (uri_path="/wp-content/plugins/work-the-flow-file-upload/" OR uri_path="*upload.php*") AND (file_extension="php" OR file_extension="exe" OR file_extension="sh" OR file_extension="py")

📊 Metadata

CVE ID: CVE-2015-10138

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-434

EPSS Score: 64.17% exploit probability (98.4th percentile)

Published: July 19, 2025

Last Updated: December 16, 2025

🔗 References

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🔗 Related Vulnerabilities

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