Why Blocking User Enumeration Is Crucial for Website Security

In the landscape of website security, there is one major overlooked issue: user enumeration in WordPress. WordPress has tried to accommodate businesses of any size with its ease of use and extensive plugin ecosystem, but this very fact turns it into a hot target for Cyber Criminals. Among all the vulnerabilities that exist in a typical WordPress site, user enumeration stands out as one of those delicate, yet dangerous threats which most website owners forget.

What is User Enumeration?

User enumeration is when hackers or malicious bots scan a website to reveal a valid username. It often takes advantage of certain functions or endpoints in WordPress that may reveal the usernames of its registered users. With a valid username, a bad actor is one step closer towards unauthorized access since now, they will only have to guess or crack the password.

How Does User Enumeration Work?

User enumeration can occur in several ways on a WordPress site:

• Author Archives: One standard method is through author archives. A site merely needs to append a query string to its URL, like “?author=1,” and the site will redirect to a URL that exposes the username associated with that ID, like yourdomain.com/author/username. This can be a very low-end but efficient way of disclosing usernames.
• Login Error Messages: Another way is by looking at the error message on the login page. Some configurations of WordPress return different errors on the login page for an invalid username versus a wrong password, which can be exploited by submitting various usernames in order to determine which are correct.
• REST API and XML-RPC: There are two other endpoints that can be used to enumerate users: WordPress’s REST API and XML-RPC. These features were designed for purposes like remote publishing and site management, but may leak usernames when queried with specific requests.
• Plugins and Themes: Some plugins and themes can leak usernames because of the type of functionality they provide. For example, user listing or directory plugins will publicize the username, while some themes won’t hide the username very well in their code or even in their URLs.

With one username revealed, the effort of carrying out subsequent brute-force attacks, phishing campaigns, or even more advanced levels of targeted social engineering is reduced. For businesses, this might translate into unauthorized access to the site, and lead to data breaches, loss of customer trust, and negative impact on brand reputation.

The Risks of Ignoring User Enumeration

Ignoring the risks to user enumeration can cause catastrophic effects. Having a valid username in hand means the attacker has already bypassed one of the two primary security barriers in order to get into your WordPress admin area. That drastically lowers the effort and time needed for unauthorized entry, and thus puts your site, data, and customers at risk.

The other point to note is this: User enumeration can potentially be a stepping stone to other attacks. Mapping usernames aids in pinpointing key staff or administrators for more advanced Phishing or Spear-Phishing efforts. At worst, this can result in full administrative access, where the attacker is able to take over your site entirely, inject whatever malicious code they’d like, or even lock you out.

Why Blocking User Enumeration Is Essential

Preventing user enumeration will help harden your WordPress site. By blocking or mitigating this vulnerability, you will be securing one of the biggest pieces of information: your username. In the absence of easy access to usernames, attackers will have to work much harder and will likely choose to move on to easier targets.

In addition, blocking user enumeration is part of a more general strategy of hardening your WordPress site against a variety of attacks. Besides protecting your website, your customers — who rely on you to keep their information safe – will have more trust in you. For enterprises, investments in the security of a website are not only a technical necessity, but a vital way to maintain credibility while avoiding costly breaches.

Leaving the security of your WordPress website to chance is not acceptable in today’s digital world. Blocking user enumeration is a highly relevant measure that needs minimal effort yet strengthens the defenses of your website. Don’t wait until it’s too late, the proactive measures taken now will help you protect your data, your customers, and your business reputation. Contact eMazzanti today and let our trained professionals help you address this issue and implement a robust security solution tailored to your needs.