CVE-2023-29438 in SimpleModal Contact Form Plugin
Summary
by MITRE • 06/26/2023
Auth. (admin+) Stored Cross-Site Scripting (XSS) vulnerability in Eric Martin SimpleModal Contact Form (SMCF) plugin <= 1.2.9 versions.
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Analysis
by VulDB Data Team • 07/18/2023
The CVE-2023-29438 vulnerability represents a critical stored cross-site scripting flaw within the Eric Martin SimpleModal Contact Form plugin for WordPress, affecting versions up to and including 1.2.9. This vulnerability specifically targets administrative users with privileges of administrator or higher, making it particularly dangerous as it allows attackers to execute malicious scripts within the context of the victim's browser session. The issue stems from inadequate input sanitization and output escaping mechanisms within the plugin's contact form handling functionality, creating an environment where malicious payloads can be persistently stored and subsequently executed when legitimate users interact with the affected plugin's interface.
The technical exploitation of this vulnerability occurs through the manipulation of form fields that are processed and stored within the WordPress database without proper sanitization. When administrators or privileged users view the stored contact form submissions or manage the plugin interface, the malicious JavaScript code embedded in the stored data executes in their browser context. This stored XSS vulnerability operates under CWE-79 which specifically addresses cross-site scripting flaws where untrusted data is improperly escaped before being rendered in web pages. The vulnerability is particularly concerning because it requires only administrative privileges to exploit, meaning that attackers who have gained access to administrator accounts or managed to escalate privileges can leverage this flaw to execute arbitrary code, steal session cookies, or perform unauthorized actions within the WordPress administration panel.
From an operational impact perspective, this vulnerability enables attackers to gain persistent access to the WordPress administration interface, potentially leading to complete compromise of the affected website. The stored nature of the XSS attack means that malicious payloads remain active until manually removed from the database, providing attackers with extended periods of access and the ability to maintain persistence. Attackers can leverage this vulnerability to inject malicious scripts that redirect users to phishing sites, steal administrative credentials, or modify website content. The impact extends beyond simple script execution as it can facilitate further attacks such as privilege escalation, data exfiltration, or the installation of backdoors within the WordPress environment. This vulnerability directly aligns with ATT&CK technique T1566.001 which covers credential harvesting through phishing and social engineering, as the XSS attack can be used to capture administrator session tokens or credentials.
Mitigation strategies for CVE-2023-29438 should prioritize immediate plugin updates to versions that have addressed this vulnerability, as the plugin developers have released patches that properly sanitize and escape user input before storage and rendering. Organizations should also implement additional security measures including regular security audits of installed plugins, implementation of web application firewalls that can detect and block XSS attempts, and strict input validation policies for all user-submitted data. Network segmentation and privileged access controls should be enforced to limit the potential impact of successful exploitation, while monitoring systems should be configured to detect unusual administrative activities that might indicate compromise. Administrators should also consider implementing Content Security Policy headers to provide additional protection against XSS attacks, and regular security training for administrators to recognize potential phishing attempts that could lead to privilege escalation. The vulnerability demonstrates the critical importance of keeping WordPress plugins updated and maintaining comprehensive security practices within web applications, as even minor flaws in third-party components can lead to complete system compromise.