Ninja Forms <= 3.14.6 - Authenticated (Administrator+) PHP Object Injection via Form Import

The Ninja Forms – The Contact Form Builder That Grows With You plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.14.6 via deserialization of untrusted input . This makes it possible for authenticated attackers, with administrator-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present. The deserialization is triggered automatically during form import when WPN_Helper::build_nf_cache() invokes $action->get_settings() immediately after the crafted form is imported, requiring no further interaction beyond the import action itself.

An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Ninja Forms 3.14.7 closes this, and updating the plugin is the step that ends it.

• Firewall
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• Alerts