WordPress Anti-Spam Plugin Vulnerability Impacts As Much As 60,000+ Sites

Posted by

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

Unauthenticated PHP Object Injection

A vulnerability was discovered in the popular Stop Spammers Security|Block Spam Users, Comments, Forms WordPress plugin.

The function of the plugin is to stop spam in remarks, kinds, 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 form that accepts a user input to only enable specific inputs, like text, images, email addresses, whatever input is anticipated.

Unforeseen inputs ought to be removed. That filtering process that keeps out unwanted inputs is called sanitization.

For example, a contact type must have a function that checks what is sent and block (sterilize) anything that is not text.

The vulnerability discovered in the anti-spam plugin enabled encoded input (base64 encoded) which can then activate a kind of vulnerability called a PHP Item injection vulnerability.

The description of the vulnerability released on the WPScan site explains the concern as:

“The plugin passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are used as 2nd difficulty, which might result in PHP Things injection if a plugin installed on the blog site has an appropriate gadget chain …”

The category of the vulnerability is Insecure Deserialization.

The non-profit Open Web Application Security Project (OWASP) explains the prospective impact of these type of vulnerabilities as severe, which may or might not be the case specific to this vulnerability.

The description at OWASP:

“The effect of deserialization defects can not be overemphasized. These defects can cause remote code execution attacks, one of the most severe attacks possible.The service effect depends on the security needs of the application and information. “But OWASP likewise keeps in mind that exploiting this kind of vulnerability tends to be challenging:”Exploitation of deserialization is somewhat hard,

as off the shelf exploits rarely work without changes or tweaks to the underlying exploit code.”The vulnerability in the Stop Spammers Security WordPress

plugin was fixed in variation 2022.6 The main Stop Spammers Security changelog (a description with dates of different updates)keeps in mind the repair as an improvement for security. Users of the Stop Spam Security plugin should think about updating to the latest

variation in order to prevent a hacker from making use of the plugin. Read the main alert at the United States Federal Government National Vulnerability Database

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

Stop Spammers Security