WordPress Plugin Vulnerability Report – Email Address Encoder – Authenticated (Contributor+) Stored Cross-Site Scripting

Q: What exactly is the vulnerability?

What exactly is the vulnerability? The vulnerability is a stored cross-site scripting issue that exists in versions 1.0.22 and earlier of the Email Address Encoder WordPress plugin. It allows attackers with contributor-level access or higher to inject malicious JavaScript code into pages and posts. This malicious code then executes when visitors load affected pages, enabling actions like cookie theft, site redirections, and malware injections. It stems from insufficient sanitization of the 'link' parameter in the plugin's eae_shortcode shortcode.

Q: How can I tell if my site has been compromised?

How can I tell if my site has been compromised? If your Email Address Encoder plugin runs an affected version, you should assume your site was compromised and take immediate action. However, possible signs of exploitation includeunexpected changes to site content, unexpected redirects or popups, new administrator accounts you didn't create, changes to existing user roles, appearance of unwanted ads or content, and unexpected files appearing in the file system. If anything seems suspicious, take the site offline immediately and request an audit from a security professional qualified to detect backdoors, malware, and other irregularities. Don't take any risks here.

Q: Is updating the plugin enough to secure my site?

Is updating the plugin enough to secure my site? While updating closes the door on this particular vulnerability vector, it's rarely enough on its own to fully secure a compromised site. Sophisticated attackers leverage vulnerabilities to install persistent backdoors giving them ongoing access even after you patch the original hole. You must determine if such backdoors exist through extensive scans by a professional. Assuming that updating the vulnerable plugin fully secures your site is dangerously naive in the aftermath of threats like this. Erring on the side of caution by taking additional auditing and hardening steps is essential.

Q: What can happen if hackers exploit this on my site?

What can happen if hackers exploit this on my site? Successful exploitation of this vulnerability opens up very serious impacts including complete site takeover, backdoored access for attackers, and ability to carry out extensive malicious actions impacting your business. Consequences include data theft, wiping or ransom of database contents, using your site to distribute malware to visitors, conducting phishing campaigns, sending spam, site defacements inserting offensive content, and more. The attacker capabilities are extensive once the initial XSS beachhead is established on vulnerable sites. This is an extremely serious vulnerability that demands immediate attention.

Q: Can I just remove the vulnerable plugin rather than updating it?

Can I just remove the vulnerable plugin rather than updating it? You can remove the Email Address Encoder plugin to eliminate the vulnerability vector. However, this will not remediate any backdoors, malware, or other artifacts left by attackers who already exploited it during the window of exposure. You still need to perform a full security audit, cleanup, and hardening after removing the plugin before considering your site secure again. Removing the plugin also obviously loses you the email encoding functionality, so updating to the fixed 1.0.23 version is preferable if you still need that protection for email addresses.

Q: Am I at risk if I'm not using the eae_shortcode shortcode?

Am I at risk if I'm not using the eae_shortcode shortcode? Yes, absolutely. The underlying vulnerability exists due to inadequate output encoding and sanitization in the Email Address Encoder plugin itself. While the attack specifically requires using the vulnerable eae_shortcode link parameter, other attack avenues leveraging the poor sanitization likely exist. You should consider any site running the affected plugin versions at high risk even if you never implemented that particular shortcode. An attacker may find other ways to exploit the filtering weakness. Updating is mandatory regardless of your direct eae_shortcode usage.

Q: What other plugins may have similar vulnerabilities?

What other plugins may have similar vulnerabilities? Plugins frequently contain vulnerabilities similar to this one that could enable an attacker to compromise your site. Some examples of other common issues include SQL injection vulnerabilities, insufficient authorization checks, PHP object injection issues, and more. All plugins have some potential to contain exploitable flaws. This reinforces why continual plugin update and monitoring for new threat advisories is so critical for WordPress site owners. Assume all plugins can serve as an attack vector until proven otherwise via ongoing auditing and patching.

Q: What can I do going forward to avoid plugin vulnerabilities?

What can I do going forward to avoid plugin vulnerabilities? The first step is to reduce your overall plugin footprint to the bare essential set. Every active plugin expands your vulnerability surface area. Next, automatically update plugins whenever new versions arise to maintain the latest security fixes. Also, subscribe to notification sources like the Wordfence threat feed that disclose newly detected flaws. Sign up at wordfence.com/blog/ to get email alerts about critical threats including vulnerable plugins. Finally, perform recurring audits to detect backdoors or anomalous behaviors indicating exploitation. Being proactive is key to sidestepping future threats.

Q: Will my web host patch this for me?

Will my web host patch this for me? Unfortunately, most basic shared web hosting providers do not actively maintain or patch the WordPress installations on their customer accounts. The responsibility ultimately falls upon you as the site owner to perform updates for plugins, themes, and WordPress core. Some managed WordPress hosts may provide patching as an advertised service, but never assume your hosting provider is updating plugins preemptively in basic shared hosting environments. You must sign in and update Email Encoder yourself to eliminate this XSS attack surface.

Q: Is this a vulnerability in WordPress itself or just the plugin?

Is this a vulnerability in WordPress itself or just the plugin? This particular vulnerability exists exclusively inside the Email Address Encoder plugin's code. It does not impact or indicate any deficiency in the core WordPress platform itself. However, plugins run with the full privileges and capabilities of the user account under which WordPress operates. So while the root cause traces solely back to the plugin's faulty coding, the impacts can still be extremely serious due to the trusted execution context coupled with insufficient isolation between plugins. But again, WordPress itself does not require any patching to resolve this specific XSS vulnerability origination from the Email Encoder plugin itself.

By Your WP Guy | November 28, 2023

Plugin Name: Email Address Encoder

Key Information:

Software Type: Plugin
Software Slug: email-address-encoder
Software Status: Active
Software Author: tillkruess
Software Downloads: 1,241,298
Active Installs: 100,000
Last Updated: November 28, 2023
Patched Versions: 1.0.23
Affected Versions: <=1.0.22

Vulnerability Details:

Name: Email Address Encoder 1.0.22 - Authenticated (Contributor+) Stored Cross-Site Scripting
Title: Authenticated (Contributor+) Stored Cross-Site Scripting
Type: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSS Score: 6.4 (Medium)
Publicly Published: November 28, 2023
Description: The Email Address Encoder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's eae_shortcode shortcode in version 1.0.22 due to insufficient input sanitization and output escaping on the 'link' user supplied attribute. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Summary:

The Email Address Encoder for WordPress has a vulnerability in versions up to and including 1.0.22 that allows authenticated users with contributor-level access or higher to inject malicious scripts that will execute when pages are loaded. This vulnerability has been patched in version 1.0.23.

Detailed Overview:

Security researcher Wordfence disclosed on November 28, 2023 an Authenticated (Contributor+) Stored Cross-Site Scripting vulnerability in the Email Address Encoder plugin affecting versions 1.0.22 and earlier. The vulnerability exists in the eae_shortcode shortcode due to insufficient sanitization of the user-supplied 'link' attribute. This could enable attackers with contributor or higher access to inject arbitrary JavaScript that would execute whenever a victim views a compromised page. This exposes WordPress sites to significant risk of compromise, cross-site scripting attacks, cookie theft, and more. Users are strongly advised to update to version 1.0.23 or higher as soon as possible to mitigate this vulnerability.

Advice for Users:

Immediate Action: Update the Email Address Encoder plugin to version 1.0.23 or higher.
Check for Signs of Vulnerability: Review your WordPress site for unexpected code or scripts, which may indicate exploitation of this vulnerability.
Alternate Plugins: While a patch is available, users might still consider alternate plugins that provide email encoding as a precaution.
Stay Updated: Always ensure that your plugins are updated to the latest versions to avoid vulnerabilities.

Conclusion:

The prompt response from the plugin developers to patch this vulnerability underscores the importance of timely updates. Users are advised to ensure that they are running version 1.0.23 or later to secure their WordPress installations.

References:

https://www.wordfence.com/threat-intel/vulnerabilities/wordpress-plugins/email-address-encoder

https://www.wordfence.com/threat-intel/vulnerabilities/wordpress-plugins/email-address-encoder/email-address-encoder-1022-authenticated-contributor-stored-cross-site-scripting

Detailed Report:

Keeping your WordPress site secure should be a top priority for any website owner. Unfortunately vulnerabilities in plugins can put that security at risk if you don't stay on top of updates. A recently disclosed vulnerability in the popular Email Address Encoder plugin underscores this need for vigilance. Earlier versions of the plugin contain a stored cross-site scripting (XSS) vulnerability that could allow attackers to inject malicious code into your site. If exploited, this could lead to your site being compromised, sensitive information stolen, or visitors infected with malware.

About the Email Address Encoder Plugin

The Email Address Encoder plugin has over 1.2 million downloads and is actively installed on over 100,000 WordPress sites. Developed by tillkruss, it provides functionality to encode email addresses on pages and posts to help protect them from email harvesting bots. Many site owners use it as an easy way to obfuscate email addresses.

Vulnerability Details

The vulnerability, tracked as CVE-2023-XXXX, affects versions 1.0.22 and earlier of Email Address Encoder. It allows authenticated users with at least Contributor access to store malicious JavaScript on vulnerable sites via Cross-Site Scripting (XSS). This JavaScript would then execute for any visiting user, enabling a range of impacts from cookie theft to malware injection.

The vulnerability exists because of insufficient input sanitization on the plugin's eae_shortcode shortcode link parameter. Exploiting this could lead to compromise of administrator sessions, site defacements, phishing attacks and more.

Risks and Potential Impacts

This vulnerability enables serious compromise of WordPress sites. Impacts may include:

Site takeover by attackers
Injection of malicious code
Cookie and session stealing
Phishing and distribution of malware to visitors
Defacements and spamming
Data exfiltration

How to Fix the Vulnerability

Email Address Encoder version 1.0.23 patches this vulnerability. Users should immediately update to the latest version. You can update the plugin directly from your WordPress dashboard. Click "Updates" and then "Check Again" to fetch the latest release.

If you suspect your site has already been compromised, take it offline and have a security professional fully audit and clean infected files.

Staying Secure

WordPress plugins continue to be a major vector for site compromises. It's critical that site owners monitor plugins for vulnerabilities and promptly update to fixed versions. Subscribe to security notification lists, monitor your plugins' changelogs, and enable automatic background updates wherever possible.

Staying on top of WordPress security can feel overwhelming for small business owners without dedicated IT staff. At Your WP Guy, we exist to shoulder that burden for you. Our WordPress experts can fully audit, secure, maintain and support your site - so you can focus on growing your business with peace of mind.

Don't tackle security risks alone. Let us help you assess any impact from this vulnerability, update your plugins, and implement ongoing maintenance to avoid future threats. We treat your website like it's our own - because we know how critical it is for reaching your customers.

Get in touch for a free consultation today on making WordPress security stress-free. Call 678-995-5169 or book a call here. Our knowledgeable team is ready to help you safeguard your online presence.

WordPress Plugin Vulnerability Report – Email Address Encoder – Authenticated (Contributor+) Stored Cross-Site Scripting FAQs

What exactly is the vulnerability?

The vulnerability is a stored cross-site scripting issue that exists in versions 1.0.22 and earlier of the Email Address Encoder WordPress plugin. It allows attackers with contributor-level access or higher to inject malicious JavaScript code into pages and posts. This malicious code then executes when visitors load affected pages, enabling actions like cookie theft, site redirections, and malware injections. It stems from insufficient sanitization of the 'link' parameter in the plugin's eae_shortcode shortcode.

How can I tell if my site has been compromised?

If your Email Address Encoder plugin runs an affected version, you should assume your site was compromised and take immediate action. However, possible signs of exploitation includeunexpected changes to site content, unexpected redirects or popups, new administrator accounts you didn't create, changes to existing user roles, appearance of unwanted ads or content, and unexpected files appearing in the file system. If anything seems suspicious, take the site offline immediately and request an audit from a security professional qualified to detect backdoors, malware, and other irregularities. Don't take any risks here.

Is updating the plugin enough to secure my site?

While updating closes the door on this particular vulnerability vector, it's rarely enough on its own to fully secure a compromised site. Sophisticated attackers leverage vulnerabilities to install persistent backdoors giving them ongoing access even after you patch the original hole. You must determine if such backdoors exist through extensive scans by a professional. Assuming that updating the vulnerable plugin fully secures your site is dangerously naive in the aftermath of threats like this. Erring on the side of caution by taking additional auditing and hardening steps is essential.

What can happen if hackers exploit this on my site?

Successful exploitation of this vulnerability opens up very serious impacts including complete site takeover, backdoored access for attackers, and ability to carry out extensive malicious actions impacting your business. Consequences include data theft, wiping or ransom of database contents, using your site to distribute malware to visitors, conducting phishing campaigns, sending spam, site defacements inserting offensive content, and more. The attacker capabilities are extensive once the initial XSS beachhead is established on vulnerable sites. This is an extremely serious vulnerability that demands immediate attention.

Can I just remove the vulnerable plugin rather than updating it?

You can remove the Email Address Encoder plugin to eliminate the vulnerability vector. However, this will not remediate any backdoors, malware, or other artifacts left by attackers who already exploited it during the window of exposure. You still need to perform a full security audit, cleanup, and hardening after removing the plugin before considering your site secure again. Removing the plugin also obviously loses you the email encoding functionality, so updating to the fixed 1.0.23 version is preferable if you still need that protection for email addresses.

Am I at risk if I'm not using the eae_shortcode shortcode?

Yes, absolutely. The underlying vulnerability exists due to inadequate output encoding and sanitization in the Email Address Encoder plugin itself. While the attack specifically requires using the vulnerable eae_shortcode link parameter, other attack avenues leveraging the poor sanitization likely exist. You should consider any site running the affected plugin versions at high risk even if you never implemented that particular shortcode. An attacker may find other ways to exploit the filtering weakness. Updating is mandatory regardless of your direct eae_shortcode usage.

What other plugins may have similar vulnerabilities?

Plugins frequently contain vulnerabilities similar to this one that could enable an attacker to compromise your site. Some examples of other common issues include SQL injection vulnerabilities, insufficient authorization checks, PHP object injection issues, and more. All plugins have some potential to contain exploitable flaws. This reinforces why continual plugin update and monitoring for new threat advisories is so critical for WordPress site owners. Assume all plugins can serve as an attack vector until proven otherwise via ongoing auditing and patching.

What can I do going forward to avoid plugin vulnerabilities?

The first step is to reduce your overall plugin footprint to the bare essential set. Every active plugin expands your vulnerability surface area. Next, automatically update plugins whenever new versions arise to maintain the latest security fixes. Also, subscribe to notification sources like the Wordfence threat feed that disclose newly detected flaws. Sign up at wordfence.com/blog/ to get email alerts about critical threats including vulnerable plugins. Finally, perform recurring audits to detect backdoors or anomalous behaviors indicating exploitation. Being proactive is key to sidestepping future threats.

Will my web host patch this for me?

Unfortunately, most basic shared web hosting providers do not actively maintain or patch the WordPress installations on their customer accounts. The responsibility ultimately falls upon you as the site owner to perform updates for plugins, themes, and WordPress core. Some managed WordPress hosts may provide patching as an advertised service, but never assume your hosting provider is updating plugins preemptively in basic shared hosting environments. You must sign in and update Email Encoder yourself to eliminate this XSS attack surface.

Is this a vulnerability in WordPress itself or just the plugin?

This particular vulnerability exists exclusively inside the Email Address Encoder plugin's code. It does not impact or indicate any deficiency in the core WordPress platform itself. However, plugins run with the full privileges and capabilities of the user account under which WordPress operates. So while the root cause traces solely back to the plugin's faulty coding, the impacts can still be extremely serious due to the trusted execution context coupled with insufficient isolation between plugins. But again, WordPress itself does not require any patching to resolve this specific XSS vulnerability origination from the Email Encoder plugin itself.

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Posted in Security, Vulnerabilities and tagged Cross-Site Scripting, email address encoder, hacks, patches, Plugin Updates, security, vulnerability, Website Maintenance, Website Security, WordPress, XSS