A WordPress anti-spam plugin with over 60,000 setups patched a PHP Item injection vulnerability that arose from inappropriate sanitization of inputs, consequently permitting base64 encoded user input.
Unauthenticated PHP Item Injection
A vulnerability was found in the popular Stop Spammers Security|Block Spam Users, Remarks, Types 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 ability for users to input IP addresses to obstruct.
It is a required practice for any WordPress plugin or form that accepts a user input to just permit specific inputs, like text, images, e-mail addresses, whatever input is anticipated.
Unforeseen inputs should be removed. That filtering process that keeps out unwanted inputs is called sanitization.
For instance, a contact type should have a function that checks what is sent and block (sterilize) anything that is not text.
The vulnerability found in the anti-spam plugin permitted encoded input (base64 encoded) which can then trigger a type of vulnerability called a PHP Item injection vulnerability.
The description of the vulnerability published on the WPScan website describes the issue as:
“The plugin passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are utilized as second obstacle, which could lead to PHP Things injection if a plugin set up on the blog has a suitable gizmo chain …”
The classification of the vulnerability is Insecure Deserialization.
The non-profit Open Web Application Security Project (OWASP) explains the potential effect of these sort of vulnerabilities as major, which may or may not be the case particular to this vulnerability.
The description at OWASP:
“The impact of deserialization flaws can not be overemphasized. These flaws can cause remote code execution attacks, among the most serious attacks possible.The company effect depends on the security requirements of the application and data. “But OWASP likewise notes that exploiting this type of vulnerability tends to be hard:”Exploitation of deserialization is somewhat hard,
as off the shelf makes use of seldom work without modifications or tweaks to the hidden 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 various updates)keeps in mind the repair as an enhancement for security. Users of the Stop Spam Security plugin should consider updating to the latest
variation in order to avoid a hacker from making use of the plugin. Check out the official notification at the United States Federal Government National Vulnerability Database
: CVE-2022-4120 Information Check out the WPScan publication of information related to this vulnerability:
Stop Spammers Security