CVE-2023-5311 – The WP EXtra plugin for WordPress versions up t... (How to Fix)

Q: What is the severity of CVE-2023-5311?

CVE-2023-5311 has a CVSS score of 8.8 (HIGH). The WP EXtra plugin for WordPress versions up to 6.2 has a missing capability check in the register() function, allowing authenticated attackers with subscriber-level permissions or higher to modify .htaccess files in critical directories. This can lead to remote code execution, affecting all WordPress sites using the vulnerable plugin.

📋 TL;DR

The WP EXtra plugin for WordPress versions up to 6.2 has a missing capability check in the register() function, allowing authenticated attackers with subscriber-level permissions or higher to modify .htaccess files in critical directories. This can lead to remote code execution, affecting all WordPress sites using the vulnerable plugin.

💻 Affected Systems

Products:

WP EXtra plugin for WordPress

Versions: Up to and including version 6.2

Operating Systems: Any OS running WordPress

Default Config Vulnerable: ⚠️ Yes

Notes: Requires WordPress installation with the WP EXtra plugin enabled and at least one user with subscriber-level permissions.

📦 What is this software?

Wp Extra by Wpvnteam

View all CVEs affecting Wp Extra →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Attackers gain full control of the WordPress site, execute arbitrary code, steal data, deface the site, or install malware.

🟠

Likely Case

Attackers modify .htaccess files to redirect traffic, inject malicious scripts, or disrupt site functionality.

🟢

If Mitigated

With proper access controls and monitoring, impact is limited to unauthorized file changes that can be detected and reverted.

🌐 Internet-Facing: HIGH, as WordPress sites are typically internet-facing, making them accessible to attackers.

🏢 Internal Only: LOW, unless the site is internally hosted and accessible only to trusted users.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires authenticated access but is straightforward due to the missing capability check.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Version 6.3 or later

Vendor Advisory: https://plugins.trac.wordpress.org/changeset/2977703/wp-extra

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Go to Plugins > Installed Plugins. 3. Find WP EXtra and update to version 6.3 or later. 4. Verify the update completes successfully.

🔧 Temporary Workarounds

Disable WP EXtra Plugin

all

Temporarily deactivate the plugin to prevent exploitation until patching is possible.

wp plugin deactivate wp-extra

Restrict User Permissions

all

Limit user accounts to only necessary roles and review subscriber-level access.

🧯 If You Can't Patch

Monitor .htaccess files in root, /wp-content, and /wp-includes directories for unauthorized changes.
Implement web application firewall (WAF) rules to block suspicious requests targeting the register() function.

🔍 How to Verify

Check if Vulnerable:

Check the WP EXtra plugin version in WordPress admin under Plugins > Installed Plugins; if version is 6.2 or lower, it is vulnerable.

Check Version:

wp plugin get wp-extra --field=version

Verify Fix Applied:

After updating, confirm the plugin version is 6.3 or higher and test that unauthorized users cannot modify .htaccess files.

📡 Detection & Monitoring

Log Indicators:

Unusual POST requests to wp-admin/admin-ajax.php with action=register
Changes to .htaccess files in critical directories

Network Indicators:

HTTP requests from authenticated users attempting to access restricted plugin functions

SIEM Query:

source="wordpress_logs" AND (uri="/wp-admin/admin-ajax.php" AND parameters.action="register")

📊 Metadata

CVE ID: CVE-2023-5311

CVSS v3 Score: 8.8 (HIGH)

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

CWE: CWE-862

Published: October 25, 2023

Last Updated: November 21, 2024

🔗 References

https://giongfnef.gitbook.io/giongfnef/cve/cve-2023-5311 Exploit,Third Party Advisory
https://plugins.trac.wordpress.org/changeset/2977703/wp-extra Patch
https://www.wordfence.com/threat-intel/vulnerabilities/id/87e3dd5e-0d77-4d78-8171-0beaf9482699?source=cve Patch,Third Party Advisory
https://giongfnef.gitbook.io/giongfnef/cve/cve-2023-5311 Exploit,Third Party Advisory
https://plugins.trac.wordpress.org/changeset/2977703/wp-extra Patch
https://www.wordfence.com/threat-intel/vulnerabilities/id/87e3dd5e-0d77-4d78-8171-0beaf9482699?source=cve Patch,Third Party Advisory

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🔗 Related Vulnerabilities

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