WordPress Anti-Spam Plugin Vulnerability Affects Approximately 60,000+ Websites

Posted by

A WordPress anti-spam plugin with over 60,000 setups covered a PHP Object injection vulnerability that occurred from incorrect sanitization of inputs, subsequently enabling base64 encoded user input.

Unauthenticated PHP Object Injection

A vulnerability was found in the popular Stop Spammers Security|Block Spam Users, Remarks, Kinds WordPress plugin.

The function of the plugin is to stop spam in remarks, forms, and sign-up registrations. It can stop spam bots and has the capability for users to input IP addresses to obstruct.

It is a needed practice for any WordPress plugin or kind that accepts a user input to just enable particular inputs, like text, images, e-mail addresses, whatever input is anticipated.

Unanticipated inputs ought to be filtered out. That filtering process that keeps out unwanted inputs is called sanitization.

For instance, a contact type must have a function that examines what is submitted and block (sanitize) anything that is not text.

The vulnerability found in the anti-spam plugin allowed encoded input (base64 encoded) which can then set off a type of vulnerability called a PHP Object injection vulnerability.

The description of the vulnerability released on the WPScan site describes the problem as:

“The plugin passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are used as 2nd difficulty, which could result in PHP Object injection if a plugin set up on the blog site has a suitable gizmo chain …”

The classification of the vulnerability is Insecure Deserialization.

The non-profit Open Web Application Security Job (OWASP) describes the prospective impact of these kinds of vulnerabilities as severe, which may or may not be the case particular to this vulnerability.

The description at OWASP:

“The effect of deserialization flaws can not be overemphasized. These defects can result in remote code execution attacks, among the most major attacks possible.The company effect depends upon the security requirements of the application and information. “But OWASP also notes that exploiting this kind of vulnerability tends to be challenging:”Exploitation of deserialization is rather challenging,

as off the rack makes use of seldom work without modifications or tweaks to the hidden exploit code.”The vulnerability in the Stop Spammers Security WordPress

plugin was repaired in variation 2022.6 The official Stop Spammers Security changelog (a description with dates of numerous updates)keeps in mind the repair as an enhancement for security. Users of the Stop Spam Security plugin ought to consider upgrading to the current

variation in order to avoid a hacker from exploiting the plugin. Check out the official alert at the United States Government National Vulnerability Database

: CVE-2022-4120 Information Check out the WPScan publication of information connected to this vulnerability:

Stop Spammers Security