CVE-2024-39665 in Filter & Grids Plugin
Summary
by MITRE • 08/02/2024
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in YMC Filter & Grids allows Stored XSS.This issue affects Filter & Grids: from n/a through 2.9.2.
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Analysis
by VulDB Data Team • 03/16/2025
This vulnerability represents a critical cross-site scripting flaw in the YMC Filter & Grids plugin that enables stored XSS attacks. The issue stems from inadequate input sanitization during web page generation processes, allowing malicious actors to inject persistent script code into the application's output. The vulnerability specifically affects versions ranging from the initial release through 2.9.2, indicating a prolonged exposure window where users remained susceptible to exploitation. This type of vulnerability falls under CWE-79 which categorizes improper neutralization of input during web page generation as a primary weakness leading to XSS attacks. The stored nature of this vulnerability means that malicious scripts are permanently saved within the application's database or storage mechanisms, making them persistently executed whenever affected pages are rendered to unsuspecting users.
The technical implementation of this flaw occurs during the web page generation phase where user-supplied data enters the application without proper sanitization or encoding before being rendered in HTML contexts. When the plugin processes filter and grid data, it fails to adequately escape or validate input parameters that are subsequently displayed in web interfaces. Attackers can exploit this by crafting malicious payloads through filter configurations or grid settings that contain embedded script tags or JavaScript code. The vulnerability is particularly dangerous because it allows attackers to execute malicious scripts in the context of the victim's browser, potentially stealing session cookies, performing unauthorized actions, or redirecting users to malicious sites. This represents a significant security gap in the input handling pipeline where data validation occurs too late in the processing chain, typically after the data has already been processed for display purposes.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking, as it provides attackers with persistent access to user sessions and potentially administrative controls within the affected application. Users who interact with pages containing the vulnerable filter or grid components become unwitting participants in the attack chain, executing malicious code that can manipulate their browsing experience or extract sensitive information. The stored nature means that even after the initial injection, the malicious code continues to execute whenever affected pages are accessed, creating a persistent threat vector that can remain undetected for extended periods. This vulnerability directly aligns with ATT&CK technique T1566 which describes social engineering attacks using malicious content, and T1059 which covers execution through scripting languages. The impact is particularly severe for WordPress environments where such plugins are commonly used for data presentation and filtering, as the attack surface expands to include numerous user interactions and dashboard elements.
Mitigation strategies should focus on immediate patching of the affected plugin to version 2.9.3 or later, which should contain proper input sanitization and output encoding mechanisms. Organizations should implement comprehensive input validation at multiple layers including client-side and server-side processing, ensuring that all user-supplied data is properly escaped before being rendered in HTML contexts. The implementation should follow secure coding practices such as context-aware output encoding, where data is encoded appropriately based on the execution context in which it will be rendered. Additionally, security headers should be implemented including Content Security Policy directives to prevent unauthorized script execution, and regular security audits should be conducted to identify similar input handling vulnerabilities across the application stack. Network monitoring should be enhanced to detect suspicious payload patterns, and user access controls should be reviewed to limit the ability of untrusted users to inject malicious content into the system. The fix should incorporate proper parameter validation and sanitization routines that prevent script injection attempts while maintaining the intended functionality of the filter and grid features.