CVE-2015-9367 in Easy Canadian Sales Taxes Add-on for iThemes Exchange
Summary
by MITRE
Easy Canadian Sales Taxes Add-on for iThemes Exchange before 1.1.0 for WordPress has XSS via add_query_arg() and remove_query_arg().
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Analysis
by VulDB Data Team • 12/07/2023
The vulnerability CVE-2015-9367 affects the Easy Canadian Sales Taxes Add-on for iThemes Exchange plugin version 1.1.0 and earlier, which is a WordPress plugin designed to handle tax calculations for Canadian sales. This security flaw represents a cross-site scripting vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. The vulnerability specifically resides in how the plugin handles URL parameters through the WordPress functions add_query_arg() and remove_query_arg().
The technical implementation of this vulnerability stems from improper sanitization of user-supplied input that gets processed through WordPress's query argument handling functions. When the plugin processes URL parameters containing malicious script code, it fails to adequately sanitize or escape these inputs before rendering them in the web page context. The add_query_arg() and remove_query_arg() functions in WordPress are typically used to manipulate URL query strings, but in this case, the plugin's implementation does not properly validate or escape the parameters before they are incorporated into dynamic web content. This creates an opportunity for attackers to inject malicious JavaScript code that executes in the context of other users' browsers when they view pages that contain the vulnerable parameters.
The operational impact of this vulnerability is significant as it allows attackers to perform various malicious activities through the compromised WordPress site. An attacker could inject scripts that steal user session cookies, redirect users to malicious websites, deface the site content, or perform actions on behalf of authenticated users. The vulnerability affects not only the plugin's functionality but also the broader WordPress installation, as it enables attackers to exploit the trust relationship between the web application and its users. Given that this is a WordPress plugin vulnerability, it could potentially be leveraged as part of broader attacks against WordPress installations, especially if the site has multiple vulnerable plugins or if the attacker can escalate privileges through other means.
Mitigation strategies for this vulnerability involve immediate patching of the affected plugin to version 1.1.0 or later, which should contain proper input sanitization and output escaping mechanisms. System administrators should also implement proper input validation at multiple layers, including validating and sanitizing all user-supplied data before processing. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and it could be categorized under ATT&CK technique T1190 for exploitation of web application vulnerabilities. Organizations should also consider implementing Content Security Policy headers to add an additional layer of protection against XSS attacks, though this does not replace proper input validation. Regular security audits of WordPress plugins and themes should be conducted to identify and remediate similar vulnerabilities before they can be exploited by threat actors.