A WordPress anti-spam plugin with over 60,000 setups patched a PHP Item injection vulnerability that arose from inappropriate sanitization of inputs, consequently enabling 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, forms, and sign-up registrations. It can stop spam bots and has the ability 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.
Unanticipated inputs ought to be removed. That filtering procedure that keeps out unwanted inputs is called sanitization.
For example, a contact type need to have a function that examines what is sent and block (sterilize) anything that is not text.
The vulnerability found 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 site describes the issue as:
“The plugin passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are utilized as 2nd difficulty, which might lead to PHP Things injection if a plugin installed on the blog has an appropriate gizmo chain …”
The classification of the vulnerability is Insecure Deserialization.
The non-profit Open Web Application Security Job (OWASP) explains the prospective impact of these sort of vulnerabilities as severe, which might or might not be the case particular to this vulnerability.
The description at OWASP:
“The effect of deserialization defects can not be overstated. These defects can lead to remote code execution attacks, among the most serious attacks possible.The organization impact depends on the protection requirements of the application and data. “But OWASP also notes that exploiting this type of vulnerability tends to be difficult:”Exploitation of deserialization is rather tough,
as off the rack exploits seldom work without changes 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 main Stop Spammers Security changelog (a description with dates of various updates)keeps in mind the fix as an improvement for security. Users of the Stop Spam Security plugin should think about updating to the most recent
variation in order to prevent a hacker from exploiting the plugin. Check out the main alert 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