CVE-2015-9371 in Manual Purchases Add-on for iThemes Exchange
Summary
by MITRE
Manual Purchases 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 identified as CVE-2015-9371 affects the Manual Purchases Add-on for iThemes Exchange version 1.0.9 and earlier, which is a WordPress plugin designed to facilitate manual order processing within e-commerce environments. This security flaw exists within the plugin's handling of URL query parameters, specifically through the manipulation of add_query_arg() and remove_query_arg() functions that are fundamental to WordPress's URL management system. The issue stems from insufficient input validation and output escaping mechanisms within the plugin's codebase, creating a pathway for malicious actors to inject malicious scripts into web pages viewed by unsuspecting users. The vulnerability is particularly concerning as it targets the core WordPress functionality used for parameter handling, making it a critical vector for cross-site scripting attacks that could compromise user sessions and data integrity.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious URL parameters that are processed through the vulnerable plugin's add_query_arg() and remove_query_arg() functions without proper sanitization. These functions are typically used to manipulate query strings in WordPress, but in this case, they fail to adequately escape or validate user-supplied input before rendering it in web responses. When legitimate users visit pages that contain these manipulated query parameters, the malicious JavaScript code embedded within the parameters executes in their browser context, potentially stealing session cookies, redirecting to malicious sites, or performing unauthorized actions on behalf of the user. The vulnerability is classified as a cross-site scripting flaw under CWE-79, which specifically addresses the improper neutralization of input during web page generation, and represents a classic example of how insecure parameter handling can lead to widespread client-side exploitation.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable sophisticated attack chains that compromise entire user sessions and potentially lead to full system compromise. Attackers could leverage this vulnerability to steal administrator credentials, modify order processing workflows, or inject malicious content that affects other users within the same WordPress environment. The vulnerability affects any user who interacts with the plugin's functionality, including both administrators and regular users who might inadvertently click on malicious links. Given that iThemes Exchange is a widely used e-commerce plugin, the potential attack surface is substantial, with the vulnerability potentially affecting thousands of WordPress installations. The exploitation requires minimal technical skill, making it particularly dangerous as it could be automated through mass phishing campaigns or social engineering attacks that target WordPress administrators.
Mitigation strategies for CVE-2015-9371 should prioritize immediate plugin updates to version 1.1.0 or later, where the vulnerability has been addressed through proper input validation and output escaping mechanisms. Organizations should implement comprehensive monitoring of their WordPress installations to identify any instances of the vulnerable plugin version, particularly in environments where multiple plugins are in use. Network-level protections such as web application firewalls can provide additional defense-in-depth by filtering suspicious query parameters before they reach the vulnerable plugin. Security teams should also conduct thorough code reviews of custom WordPress plugins to ensure that all parameter handling follows secure coding practices, particularly around the use of WordPress's built-in functions that manipulate URL parameters. The vulnerability demonstrates the critical importance of proper input validation and output escaping as outlined in the OWASP Top Ten and aligns with ATT&CK technique T1213 for data from information repositories, highlighting the need for robust parameter handling in web applications. Regular security assessments and vulnerability scanning should be implemented to identify similar issues in other WordPress plugins and themes, as this vulnerability represents a common pattern in web application security flaws.