MW WP Form Vulnerability – Improper Limitation of File Name to Unauthenticated Arbitrary File Deletion – CVE-2023-6559 | WordPress Plugin Vulnerability Report

What is the MW WP Form plugin?

The MW WP Form plugin is a popular WordPress contact form plugin used by over 200,000 websites. It allows site owners to easily create customized contact forms such as lead capture forms, email signup forms, online reservation forms, and more. With over 1.5 million downloads, it is one of the most widely installed contact form plugins in the WordPress ecosystem.

MW WP Form is made by the developer inc2734 and is currently at version 5.0.4 as of December 2023. It is generally well-reviewed and feature-rich, making it a common choice for site contact form needs.

What is the vulnerability impacting this plugin?

A path traversal vulnerability was disclosed impacting MW WP Form versions 5.0.3 and below in mid-December 2023. This type of flaw allows attackers to improperly access files outside intended directories by manipulating file paths.

Specifically, the vulnerability allows unauthenticated attackers (those without login access) to delete sensitive WordPress files by sending crafted requests that bypass validation checks in the plugin code for deletions. This makes it possible to delete critical files like wp-config.php which contains database credentials.

Most dangerously, complete site takeover could occur if attackers leverage the vulnerability to inject backdoors, malware or malicious redirects by overwriting key files. So the flaw enables several stages of potential compromise.

How can this vulnerability be exploited?

To exploit this, attackers would target an outdated MW WP Form installation and send manipulated requests to delete files. As the plugin does not properly validate paths prior to deletion in vulnerable versions, crafted strings allow escaping out restricted directories.

For example, using “../” sequences in the path can traverse to higher level directories like the main WordPress installation. With write access from the plugin, attackers can then erase sensitive files. They may also try to upload backdoors or malicious scripts by overwriting existing plugin files.

No authentication is required for vulnerability exploitation, making vulnerable sites easy to probe and attack. Basic hacking tools and techniques allow identifying outdated sites and attempting deletion requests, though advanced skills heighten harm possibilities through scripts uploaded afterward.

How serious is this vulnerability?

This MW WP Form vulnerability is considered highly severe. It has been assigned a CVSS severity score of 7.5 out of 10 by security researchers. The two primary factors making it high risk are:

1. It can be exploited anonymously without needing any login access.
2. The potential impacts range from data loss up to complete site takeover.

In the worst case scenarios, attackers could steal or delete all site data, implant malware to infect visitors, and fully control site content and operations. Even milder outcomes like wp-config.php deletion remain highly damaging by exposing database credentials. So all sites running the affected plugin versions are at substantial risk until updating.

What plugin versions are affected?

MW WP Form versions 5.0.3 and below contain the vulnerability and require urgent updating. Version 5.0.4 has patched this particular file deletion flaw.

However, even sites running the latest 5.0.4 release may still be vulnerable to some degree, as three other security issues have impacted the plugin since May 2023. These previous flaws open other potential attack vectors, though the unauthenticated file deletion danger poses the most overall risk currently.

In general, sites should aim to run the newest plugin releases as they contain cumulative security fixes. But the file manipulation issue in 5.0.3 and lower is particularly critical and easy to exploit anonymously.

Is updating enough to fully protect sites?

Updating to the latest patched release, version 5.0.4, is highly recommended as the first step to close this specific vulnerability vector. However, additional precautions may be wise due to the history of recurring flaws in MW WP Form.

Firstly, site owners should examine logs after updating for signs of any unauthorized prior file changes. Attackers may already have modified key files in preceding vulnerable versions. Reverting tampered files and changing credentials may be required on compromised sites even after applying the update.

Additionally, choosing a different contact form plugin is a cautious option to consider. Popular alternative good choices include Contact Form 7, Gravity Forms or Ninja Forms which do not carry the repeated vulnerabilities of MW WP Form. While updating resolves the current situation, the plugin’s track record suggests lingering risks. Changing solutions avoids its uncertain future.

Why do flaws keep appearing in this plugin?

The number of vulnerabilities uncovered in MW WP Form since mid-2023 suggests fundamental flaws in its overall security approach, not just one-off issues. Four severe bugs emerging rapidly indicates developers have not prioritized safe coding practices or rigorous testing.

Easy oversights like failing to validate file paths show a lack of basic secure development knowledge. This results in easily avoidable vulnerabilities that then expose site owners to serious risk. It violates user trust and reflects negligence around security principles in engineering the plugin.

While the quick patching turnaround is positive, many sites remain on old versions missing fixes for weeks or longer. The company must refocus efforts on “security by design” to identify and resolve structural program weaknesses. Failing to build preventative measures will continue prompting urgent fire drills whenever new flaws inevitably emerge.

What security steps should WordPress site owners take?

Maintaining strong security is an ongoing process for WordPress sites, not a one-time fix. Key recommended steps site owners should take include:

• Review plugins/themes and remove any unnecessary ones to minimize your exposure area. Leaner is safer.
• Establish automatic background updates for WordPress core, plugins and themes so you effortlessly stay on newest releases.
• Install a security plugin to detect and block common attacks or malware signatures. Wordfence and Sucuri offer good options.
• Use strong passwords, limit admin users, and confirm regular data backups to prepare best for any future incidents.

Site software is deeply complex, so new vulnerabilities constantly arise. Staying vigilant to apply rapid updates the moment dangers appear keeps your business resilient. Don’t wait until disaster strikes to make security an priority.

What options exist for WordPress security management?

Realistically assessing your team’s available time and security proficiency is wise when evaluating options to handle WordPress security:

If your staff lacks specialized expertise but can dedicate consistent hours, training yourself combined with using security software suites is the most budget-friendly path to direct security management. Learning WordPress security fundamentals while utilizing tools like Wordfence enables in-house ongoing oversight.

For busier teams lacking extra capacity, enlisting an expert managed hosting provider to fully handle security operations offers assurance. Specialists actively monitor threats, release updates, provide layers of protection, and combat attacks so you avoid that burden. This outsourced security function reduces business disruption risks.

Balancing cost, risk and workload, honest self-evaluation guides the decision between self-managed or fully managed security. Don’t overestimate team capabilities as sites grow more complex, but leverage experienced provider solutions if you lack capacity internally.

Where can I learn more about WordPress security?

WordPress security encompasses a wide range of ever-evolving threats, solutions and best practices. Some recommended resources to continually expand your knowledge include:

• The WordPress Developer Blog – Regular security notices on new threats and fixes.
• WordPress Codex Security Guide – Reference for configuring built-in security tools.
• Google’s Web Fundamentals – General good web security practices.
• WordPress Security Podcasts – Convenient way to keep updated on the go. Examples include “The Big Braintrust” and “The Secure Developer”.
• Ongoing education courses – Structured programs like InfoSec Institute sharpen practical skills.

Learning WordPress security requires continued curiosity as landscapes change rapidly. Combining multiple free and paid resources trains well-rounded competencies to make sites safer, whether handling in-house or through providers. The more you know, the lower your business risk becomes.