CVE-2015-9377 in iThemes Builder Theme Depot
Summary
by MITRE
iThemes Builder Theme Depot before 5.0.30 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-2015-9377 affects the iThemes Builder Theme Depot plugin version prior to 5.0.30 for WordPress, representing a cross-site scripting flaw that can be exploited by malicious actors to execute arbitrary code within the context of a user's browser. This vulnerability specifically resides in the plugin's handling of URL parameters through the add_query_arg() and remove_query_arg() functions, which are fundamental WordPress utility functions used for manipulating query strings in URLs. The flaw allows attackers to inject malicious scripts into URLs that are then executed when users navigate to affected pages, creating a persistent threat vector that can compromise user sessions and potentially lead to full system compromise.
The technical implementation of this vulnerability stems from improper input validation and output sanitization within the plugin's codebase. When the plugin processes user-supplied parameters through the add_query_arg() and remove_query_arg() functions, it fails to adequately sanitize or escape the data before incorporating it into HTML output. This creates a classic XSS attack surface where malicious payloads can be embedded in URL parameters and subsequently rendered in web pages without proper security controls. The vulnerability is particularly concerning because it leverages core WordPress functions that are extensively used throughout the platform, making it difficult to detect and mitigate without comprehensive patching of the affected plugin.
The operational impact of CVE-2015-9377 extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, data theft, and privilege escalation within the WordPress environment. Users who visit compromised pages may unknowingly execute malicious JavaScript that can steal authentication cookies, redirect them to phishing sites, or inject additional malicious code into the victim's browser. The vulnerability affects any WordPress site running an affected version of the iThemes Builder Theme Depot plugin, making it a widespread concern for website administrators who may not be actively monitoring plugin updates. Attackers can exploit this vulnerability by crafting malicious URLs with encoded script payloads that are then processed by the vulnerable plugin functions, potentially leading to complete compromise of user accounts and website integrity.
Mitigation strategies for CVE-2015-9377 require immediate action from affected website administrators, primarily focusing on updating the iThemes Builder Theme Depot plugin to version 5.0.30 or later where the vulnerability has been addressed. Security professionals should implement comprehensive monitoring of plugin versions across their WordPress installations and establish automated update mechanisms where possible. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting the sources from which scripts can be loaded. According to CWE guidelines, this vulnerability maps to CWE-79, which describes Cross-site Scripting flaws in web applications, and aligns with ATT&CK technique T1059.007 for Scripting, as it enables attackers to execute malicious scripts through web-based interfaces. Organizations should also conduct regular security audits of their WordPress plugins and maintain up-to-date vulnerability databases to quickly identify and remediate similar issues across their digital infrastructure.