A WordPress anti-spam plugin with over 60,000 installations patched a PHP Item injection vulnerability that developed from inappropriate sanitization of inputs, subsequently allowing base64 encoded user input.
Unauthenticated PHP Things Injection
A vulnerability was discovered in the popular Stop Spammers Security|Block Spam Users, Remarks, Types WordPress plugin.
The purpose of the plugin is to stop spam in comments, 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 required practice for any WordPress plugin or type that accepts a user input to just permit particular inputs, like text, images, e-mail addresses, whatever input is expected.
Unforeseen inputs need to be filtered out. That filtering procedure that stays out unwanted inputs is called sanitization.
For instance, a contact kind must have a function that examines 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 set off a kind of vulnerability called a PHP Item injection vulnerability.
The description of the vulnerability released on the WPScan website describes the problem as:
“The plugin passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are used as 2nd obstacle, which might cause PHP Item injection if a plugin set up on the blog has an appropriate gizmo chain …”
The category of the vulnerability is Insecure Deserialization.
The non-profit Open Web Application Security Job (OWASP) describes the possible impact of these kinds of vulnerabilities as major, which might or might not hold true particular to this vulnerability.
The description at OWASP:
“The impact of deserialization flaws can not be overstated. These flaws can lead to remote code execution attacks, one of the most major attacks possible.The service effect depends on the security needs of the application and information. “However OWASP also keeps in mind that exploiting this type of vulnerability tends to be hard:”Exploitation of deserialization is somewhat hard,
as off the shelf makes use of hardly ever work without modifications or tweaks to the hidden make use of code.”The vulnerability in the Stop Spammers Security WordPress
plugin was repaired in version 2022.6 The official Stop Spammers Security changelog (a description with dates of various updates)notes the fix as an improvement for security. Users of the Stop Spam Security plugin need to consider updating to the current
version in order to avoid a hacker from making use of the plugin. Read the main alert at the United States Government National Vulnerability Database
: CVE-2022-4120 Information Check out the WPScan publication of information associated with this vulnerability:
Stop Spammers Security