CVE-2017-18574 in ninja-forms Plugin
Summary
by MITRE
The ninja-forms plugin before 3.0.31 for WordPress has insufficient HTML escaping in the builder.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/01/2023
The vulnerability identified as CVE-2017-18574 affects the ninja-forms WordPress plugin version 3.0.30 and earlier, representing a critical security flaw in the plugin's form builder functionality. This issue stems from inadequate HTML escaping mechanisms within the plugin's codebase, specifically impacting how user-generated content is processed and rendered within the administrative interface. The vulnerability exists in the plugin's handling of form field data, where input values are not properly sanitized before being displayed in the builder environment, creating a potential vector for cross-site scripting attacks.
The technical flaw manifests in the plugin's insufficient sanitization of HTML content when rendering form elements within the WordPress admin dashboard. When administrators or users interact with form builder interfaces, the plugin fails to adequately escape special characters and HTML tags in user inputs, allowing malicious actors to inject arbitrary HTML or JavaScript code. This weakness directly maps to CWE-79, which describes Cross-Site Scripting vulnerabilities resulting from improper input sanitization. The vulnerability is particularly dangerous because it operates within the privileged WordPress admin context, where successful exploitation could enable attackers to execute malicious scripts in the browsers of administrators who view affected forms.
The operational impact of this vulnerability extends beyond simple data corruption or display issues, as it creates a persistent threat vector that could be exploited by attackers with varying levels of access. An attacker who gains the ability to modify form fields through legitimate means could inject malicious scripts that would execute whenever administrators view or edit forms within the builder interface. This scenario aligns with ATT&CK technique T1566, which covers social engineering tactics involving the manipulation of user interfaces to facilitate further compromise. The vulnerability affects WordPress installations where the ninja-forms plugin is active, potentially compromising entire sites if administrators are tricked into interacting with maliciously crafted forms.
Mitigation strategies for CVE-2017-18574 require immediate action to upgrade the ninja-forms plugin to version 3.0.31 or later, which includes proper HTML escaping mechanisms. Organizations should also implement additional security measures such as restricting administrative access to trusted users only, implementing content security policies to limit script execution, and conducting regular security audits of installed plugins. The vulnerability demonstrates the critical importance of input validation and output sanitization in web applications, particularly in administrative interfaces where privileged users interact with potentially untrusted data. Regular plugin updates and security monitoring are essential practices to prevent exploitation of similar vulnerabilities in other WordPress components.