Introduction to CVE-2017-14990
WordPress is one of the most widely used Content Management System (CMS) platforms in the world today. As a result, it has been a major target for security researchers and cybercriminals alike. CVE-2017-14990 is a vulnerability discovered in older versions of WordPress, specifically those before version 4.8.3.
This vulnerability relates to the way WordPress stores signup activation keys. Instead of using a secure hashing method, WordPress stored these keys in plaintext, exposing them to potential misuse if an attacker gained access to the database.
What is the WordPress wp signups Activation Key?
In a WordPress Multisite installation, there is a database table called wp signups. Within this table, one column is named activation key. This key is automatically generated when a user registers for an account or creates a new website within the multisite network.
WordPress sends the activation key via an email link, allowing users to activate and verify their account. The core issue was that WordPress stored these activation keys in unencrypted (plaintext) form in the database.
How the Vulnerability Works
Because activation keys were stored in plaintext, any attacker who gained access to the database through SQL injection, stolen database dumps, weak server configuration, or leaked credentials could immediately read all activation keys without any further effort.
Since no hashing was applied to these keys, an attacker could misuse them to manipulate account activations or abuse the registration process. However, this vulnerability on its own did not allow attackers to execute remote code on the server.
Why Cleartext Storage is Dangerous
Cleartext storage means data is saved exactly as provided, with no encryption or hashing applied. This is dangerous because anyone with access to the database can immediately read and use the stored data.
To prevent misuse, passwords and tokens should never be stored in their original form. Applications typically use hash functions to reduce the damage caused by data breaches. Cleartext storage of activation keys allows attackers to use those keys directly, without needing to crack any codes.
Which WordPress Versions Were Affected?
CVE-2017-14990 affected all versions of WordPress before 4.8.3. The problem was specifically tied to the WordPress Multisite feature, where activation keys were stored insecurely. Users running any version prior to 4.8.3 were at higher risk because those versions did not have the necessary security measures in place.
How Attackers Can Exploit CVE-2017-14990
Attackers generally require database access before exploiting this vulnerability. That access could come from weak passwords, compromised hosting environments, vulnerable plugins, or SQL injection flaws.
Once inside the database, an attacker can query the wp signups table and retrieve activation keys. These keys can then be used to manipulate account activations or abuse the registration process.
Example of Cleartext Activation Key Storage
In a vulnerable setup, the database might store an activation key in a form that is directly readable, for example:
Activation key = abc123xyz
Because the value is stored as-is, any attacker with database access can read and use it immediately.
Example of Secure Hashed Storage
A more secure system stores activation keys as hashed values, for example:
Activation key = $2y$10$e0NRm9KFWRbB7vEDx…
Hashed values (such as those produced by bcrypt) cannot be easily reversed to their original form, making them significantly safer to store. Modern security standards recommend bcrypt or Argon2 for hashing tokens and passwords.
Common Attack Scenarios
One common scenario involves exploiting a vulnerable plugin to gain SQL access. Once inside, the attacker queries the database for activation keys and uses them to abuse the account registration process.
Another scenario involves database backups that were inadvertently stored in publicly accessible server directories. An attacker who downloads such a backup instantly has access to all plaintext activation keys.
Real Security Risks of This Vulnerability
Although this vulnerability was not rated as critical on its own, it made other attacks more likely to succeed. Cleartext storage means that leaked data is instantly usable, reducing the effort required by an attacker to cause harm.
Risks associated with this vulnerability included:
- Abuse of account activation and registration systems
- User privacy concerns due to exposed registration data
- Potential for lateral movement across multisite installations managing many users and websites
How WordPress Fixed the Issue
WordPress addressed this vulnerability in version 4.8.3 by introducing hashing for activation keys stored in the wp signups table. Instead of saving keys in plaintext, the updated code applies a hash before storing them, ensuring that even if the database is exposed, the raw keys cannot be retrieved directly.
These changes significantly reduced the risk of activation key misuse and brought WordPress in line with modern security best practices for handling tokens and authentication data.
How to Protect Your WordPress Website
Staying current with your WordPress version is critical. Website owners should always keep their WordPress installation, themes, and plugins up to date. Secure database credentials and a hardened hosting environment are equally important.
Administrators should avoid using outdated or unsupported themes and plugins, as inactive components may still contain exploitable vulnerabilities. Using security plugins that offer login monitoring, firewall protection, and activity logging adds another layer of defence.
Best Security Practices for WordPress Users
WordPress users should follow a layered security approach. Strong passwords, two-factor authentication, and regular backups are essential for protecting a website.
It is also important to remove unused plugins and themes, because inactive components may still contain vulnerabilities that attackers can exploit.
Importance of Database Security
Database security is critical for protecting websites. Even a minor flaw becomes a serious threat once an attacker gains direct access to the database.
Applying proper access permissions, firewall rules, secure backups, and restricted database access significantly reduces exposure risks. Website administrators should also monitor for suspicious database activity on a regular basis.
Difference Between Hashed and Cleartext Storage
Cleartext storage saves data in its original form, making it immediately readable by anyone with database access. Hashing converts data into a fixed-length string using a mathematical algorithm, and this process is designed to be irreversible.
Hashed storage is far more secure because an attacker cannot easily retrieve the original values. In modern software, sensitive data such as passwords and tokens is stored using hashing algorithms rather than in plaintext.
How to Check If Your Website is Vulnerable
Website owners can check their WordPress version in the dashboard under Dashboard > Updates. If the installation is running a version prior to 4.8.3, it should be updated immediately. Administrators can also audit the database to verify how activation keys are stored.
Using security scanning plugins or dedicated vulnerability scanners compatible with the CVE database can help identify whether any part of the website remains outdated or exposed.
Should You Update Old WordPress Versions?
Running an outdated version of WordPress is extremely risky. Exploits for old versions are well documented and widely known among attackers, who actively look for sites running discontinued software. Updates not only improve security but also enhance compatibility and performance.
Conclusion
CVE-2017-14990 highlighted the importance of secure data storage practices in web applications and WordPress hosting environments. Although the vulnerability primarily affected activation key management within WordPress Multisite installations running versions before 4.8.3, it demonstrated how plaintext storage can dramatically increase the impact of a database breach. Modern cybersecurity standards strictly advise against storing sensitive data in plaintext. Keeping your WordPress installation up to date remains one of the most effective steps you can take to protect your website.