CVE-2022-4196 in Multi Step Form Plugin
Summary
by MITRE • 01/10/2023
The Multi Step Form WordPress plugin before 1.7.8 does not sanitise and escape some of its form fields, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/09/2025
The vulnerability identified as CVE-2022-4196 affects the Multi Step Form WordPress plugin version 1.7.7 and earlier, representing a critical security flaw that enables stored cross-site scripting attacks through improper input sanitization. This vulnerability specifically targets high-privilege users such as administrators who possess the capability to manipulate form fields within the plugin's interface. The flaw exists in the plugin's handling of user input data where form fields are not properly sanitized or escaped before being stored and subsequently rendered back to users. The issue becomes particularly dangerous in multisite WordPress configurations where the unfiltered_html capability is typically restricted to prevent malicious code injection. When this capability is disabled, the vulnerability persists because the plugin fails to implement adequate sanitization measures for its form processing functionality.
The technical implementation of this vulnerability stems from the plugin's failure to apply proper input validation and output escaping mechanisms for form data. According to CWE-79, which categorizes cross-site scripting vulnerabilities, the root cause lies in the inadequate sanitization of user-supplied data that is then reflected in web pages without proper encoding or filtering. This allows attackers with administrative privileges to inject malicious scripts into form fields that are subsequently stored in the database and executed when other users view the affected forms. The vulnerability operates at the application layer and specifically targets the plugin's form handling mechanisms, where user inputs are processed and stored without sufficient security controls. The flaw demonstrates a lack of defense-in-depth principles in the plugin's code architecture, as it fails to implement proper input validation even when the WordPress core security measures are in place to restrict HTML content.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with persistent access to administrative functions and potentially allows for privilege escalation within the WordPress environment. When an administrator creates or modifies forms using the vulnerable plugin, malicious scripts can be embedded in form fields that will execute whenever the form data is displayed to other users. This stored XSS attack vector enables attackers to perform actions such as stealing user sessions, modifying form data, redirecting users to malicious websites, or even gaining unauthorized access to the WordPress administration panel. The vulnerability is particularly concerning in multisite environments where administrators may have limited control over individual site configurations but can still exploit this weakness to compromise multiple sites within the network. The attack requires minimal privileges, as only an administrative user account is needed to inject malicious code, making it a significant threat to WordPress multisite deployments.
Mitigation strategies for CVE-2022-4196 involve immediate plugin updates to version 1.7.8 or later, which contain the necessary sanitization fixes. Administrators should also implement additional security measures including regular security audits of installed plugins, monitoring for suspicious form modifications, and ensuring proper capability restrictions are enforced across all user roles. The WordPress security team recommends that administrators verify their plugin installations and confirm that all security patches are applied promptly. Organizations should also consider implementing web application firewalls to detect and block suspicious script injection attempts, while maintaining regular backups to ensure quick recovery in case of successful exploitation. The vulnerability highlights the importance of proper input validation and output escaping as outlined in the OWASP Top Ten security principles, specifically addressing the need for secure coding practices that prevent XSS vulnerabilities through proper data sanitization at all points in the application lifecycle. Additionally, security monitoring should include detection of unusual form modifications and unauthorized script injections to identify potential exploitation attempts.