CVE-2017-18489 in contact-form-7-sms-addon Plugin
Summary
by MITRE
The contact-form-7-sms-addon plugin before 2.4.0 for WordPress has XSS.
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Analysis
by VulDB Data Team • 11/23/2023
The contact-form-7-sms-addon plugin for WordPress contains a cross-site scripting vulnerability that affects versions prior to 2.4.0, representing a critical security flaw in the plugin ecosystem. This vulnerability arises from insufficient input validation and output sanitization within the plugin's handling of user-supplied data, specifically when processing SMS form submissions and related parameters. The flaw allows attackers to inject malicious scripts into the plugin's response handling, potentially compromising the security of WordPress installations that rely on this addon for contact form functionality.
The technical implementation of this XSS vulnerability stems from the plugin's failure to properly escape and validate user input before rendering it in HTML contexts. When users submit SMS form data through the contact-form-7 integration, the plugin processes this information without adequate sanitization measures, creating an environment where malicious actors can inject script code into the response. This occurs particularly when the plugin displays form data or error messages containing unescaped user input, enabling attackers to execute arbitrary JavaScript in the context of other users' browsers. The vulnerability can be exploited through various vectors including form submission parameters, error messages, or any field that accepts user input and displays it back to users without proper encoding.
The operational impact of this vulnerability extends beyond simple script execution, potentially enabling attackers to perform session hijacking, defacement of web pages, data theft, or redirection to malicious sites. An attacker could craft a malicious SMS form submission that, when processed by the vulnerable plugin, would execute malicious JavaScript in the browser of any user who views the affected page or interacts with the compromised form. This could lead to unauthorized access to WordPress administrative panels, data exfiltration, or further exploitation of the compromised WordPress installation. The vulnerability is particularly dangerous because it leverages the legitimate functionality of the contact form plugin, making it harder to detect and distinguish from normal user activity. This type of vulnerability is categorized under CWE-79 as "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", which is a fundamental web application security weakness that affects the integrity of user sessions and data.
Mitigation strategies for this vulnerability require immediate patching of the contact-form-7-sms-addon plugin to version 2.4.0 or later, which includes proper input validation and output sanitization measures. Organizations should implement comprehensive security monitoring to detect potential exploitation attempts and ensure that all WordPress plugins are kept up to date with the latest security patches. Additionally, administrators should consider implementing Content Security Policy headers to limit script execution and reduce the impact of potential XSS attacks. The vulnerability aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript' and represents a common attack pattern that demonstrates the importance of proper input validation in web applications. Security teams should also consider implementing web application firewalls to detect and block malicious script injection attempts, while maintaining regular security audits of all installed WordPress plugins to identify potential vulnerabilities before they can be exploited by threat actors.