CVE-2025-22303 – This vulnerability in WP Mailster WordPress plu... (How to Fix)

Q: What is the severity of CVE-2025-22303?

CVE-2025-22303 has a CVSS score of 5.3 (MEDIUM). This vulnerability in WP Mailster WordPress plugin allows attackers to retrieve embedded sensitive data from sent emails. It affects all WP Mailster installations from unknown versions through 1.8.17.0. WordPress site administrators using this plugin are affected.

📋 TL;DR

This vulnerability in WP Mailster WordPress plugin allows attackers to retrieve embedded sensitive data from sent emails. It affects all WP Mailster installations from unknown versions through 1.8.17.0. WordPress site administrators using this plugin are affected.

💻 Affected Systems

Products:

WP Mailster WordPress Plugin

Versions: n/a through 1.8.17.0

Operating Systems: All

Default Config Vulnerable: ⚠️ Yes

Notes: All WordPress installations with WP Mailster plugin enabled are vulnerable.

📦 What is this software?

Wp Mailster by Wpmailster

View all CVEs affecting Wp Mailster →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Attackers could extract sensitive information like passwords, API keys, or personal data embedded in emails sent through the plugin, leading to data breaches and credential theft.

🟠

Likely Case

Unauthorized access to email content containing sensitive information, potentially exposing user data or system credentials.

🟢

If Mitigated

Limited exposure if emails contain no sensitive data or if plugin is not used for sensitive communications.

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Based on CWE-201 (Insertion of Sensitive Information Into Sent Data), exploitation likely involves accessing improperly exposed data.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Versions after 1.8.17.0

Vendor Advisory: https://patchstack.com/database/wordpress/plugin/wp-mailster/vulnerability/wordpress-wp-mailster-plugin-1-8-17-0-sensitive-data-exposure-vulnerability?_s_id=cve

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find WP Mailster and update to latest version. 4. Verify update completes successfully.

🔧 Temporary Workarounds

Disable WP Mailster Plugin

all

Temporarily disable the vulnerable plugin until patched.

wp plugin deactivate wp-mailster

🧯 If You Can't Patch

Disable WP Mailster plugin immediately.
Use alternative email plugins for WordPress.

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin panel > Plugins > Installed Plugins for WP Mailster version 1.8.17.0 or earlier.

Check Version:

wp plugin get wp-mailster --field=version

Verify Fix Applied:

Verify WP Mailster version is higher than 1.8.17.0 in WordPress admin panel.

📡 Detection & Monitoring

Log Indicators:

Unusual access patterns to email-related endpoints
Multiple failed attempts to access plugin files

Network Indicators:

HTTP requests to wp-mailster plugin endpoints with suspicious parameters

SIEM Query:

source="wordpress" AND (uri_path="/wp-content/plugins/wp-mailster/*" OR plugin="wp-mailster")

📊 Metadata

CVE ID: CVE-2025-22303

CVSS v3 Score: 5.3 (MEDIUM)

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

CWE: CWE-201

EPSS Score: 0.16% exploit probability (36.6th percentile)

Published: January 7, 2025

Last Updated: February 11, 2025

🔗 References

https://patchstack.com/database/wordpress/plugin/wp-mailster/vulnerability/wordpress-wp-mailster-plugin-1-8-17-0-sensitive-data-exposure-vulnerability?_s_id=cve Third Party Advisory

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