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

Posted by

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

Unauthenticated PHP Things Injection

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

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

It is a required practice for any WordPress plugin or kind that accepts a user input to only permit specific inputs, like text, images, e-mail addresses, whatever input is expected.

Unanticipated inputs need to be filtered out. That filtering procedure that keeps out unwanted inputs is called sanitization.

For instance, a contact type should have a function that checks what is submitted and block (sterilize) anything that is not text.

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

The description of the vulnerability published on the WPScan site explains the problem as:

“The plugin passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are utilized as second obstacle, which might result in PHP Things injection if a plugin set up on the blog site has an appropriate device chain …”

The category of the vulnerability is Insecure Deserialization.

The non-profit Open Web Application Security Project (OWASP) explains the potential impact of these sort of vulnerabilities as major, which might or may not be the case particular to this vulnerability.

The description at OWASP:

“The impact of deserialization defects can not be overstated. These flaws can lead to remote code execution attacks, one of the most serious attacks possible.The business impact depends on the defense requirements of the application and data. “But OWASP also keeps in mind that exploiting this type of vulnerability tends to be challenging:”Exploitation of deserialization is rather challenging,

as off the rack exploits rarely work without modifications or tweaks to the hidden make use of code.”The vulnerability in the Stop Spammers Security WordPress

plugin was repaired in variation 2022.6 The main Stop Spammers Security changelog (a description with dates of various updates)notes the fix as an enhancement for security. Users of the Stop Spam Security plugin must consider upgrading to the most recent

version in order to avoid a hacker from making use of the plugin. Check out the official notice at the United States Federal Government National Vulnerability Database

: CVE-2022-4120 Detail Check out the WPScan publication of details related to this vulnerability:

Stop Spammers Security