CVE-2022-4004 in Donation Button Plugin
Summary
by MITRE • 12/12/2022
The Donation Button WordPress plugin through 4.0.0 does not properly check for privileges and nonce tokens in its "donation_button_twilio_send_test_sms" AJAX action, which may allow any users with an account on the affected site, like subscribers, to use the plugin's Twilio integration to send SMSes to arbitrary phone numbers.
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Analysis
by VulDB Data Team • 01/07/2023
The vulnerability identified as CVE-2022-4004 affects the Donation Button WordPress plugin version 4.0.0 and earlier, presenting a critical privilege escalation issue within the plugin's AJAX handling mechanism. This flaw stems from insufficient access controls and nonce validation in the "donation_button_twilio_send_test_sms" endpoint, which is designed to facilitate sending test SMS messages through Twilio integration. The vulnerability allows any authenticated user account on the WordPress site to exploit this functionality without proper authorization, creating a significant security risk that extends beyond typical user permissions.
The technical implementation of this vulnerability resides in the plugin's failure to validate user privileges and nonce tokens before executing the SMS sending functionality. In WordPress environments, AJAX actions that interact with external services like Twilio should always verify that the requesting user possesses appropriate permissions and that the request originates from a legitimate source through nonce validation. The absence of these security checks means that even low-privilege users such as subscribers can invoke the Twilio SMS sending capability through the plugin's administrative interface, bypassing the intended access controls that should restrict such functionality to administrators or authorized personnel.
From an operational perspective, this vulnerability creates substantial risk for affected WordPress installations, particularly those utilizing the Donation Button plugin for fundraising activities. An attacker with access to any user account can leverage this flaw to send unsolicited SMS messages to arbitrary phone numbers, potentially leading to spamming, phishing campaigns, or social engineering attacks. The impact extends beyond simple abuse, as it could result in financial losses through unauthorized messaging charges, damage to reputation, and potential compliance violations regarding unsolicited communications. The vulnerability also enables attackers to enumerate phone numbers used within the organization's contact database, as they can test various numbers to determine which ones are registered with the Twilio service.
The vulnerability aligns with CWE-863, which addresses "Incorrect Authorization," and represents a clear violation of the principle of least privilege in software security design. From an ATT&CK framework perspective, this issue maps to T1566, "Phishing," as it enables the creation of SMS-based phishing campaigns, and T1071.004, "Application Layer Protocol: DNS," since the Twilio integration may involve DNS resolution for service communication. The flaw also demonstrates characteristics of T1190, "Exploit Public-Facing Application," as it represents an unauthenticated attack vector that can be exploited through the WordPress plugin interface. Organizations should implement immediate mitigations including updating to the patched version of the plugin, implementing proper access controls, and monitoring for unauthorized SMS sending activities.
The recommended mitigation strategy involves applying the vendor-supplied patch that addresses the privilege checking and nonce validation issues in the plugin's AJAX handler. Additionally, administrators should review and restrict user roles to ensure that only trusted personnel have access to sensitive plugin functionalities. Network-level monitoring should be implemented to detect unusual SMS sending patterns, and the Twilio integration should be configured with proper rate limiting and message tracking capabilities. Organizations should also consider implementing additional security controls such as two-factor authentication for administrative access and regular security audits of installed plugins to identify similar privilege escalation vulnerabilities. The vulnerability highlights the critical importance of proper input validation and access control implementation in web applications, particularly when dealing with external service integrations that can be leveraged for malicious purposes.