CVE-2021-4424 in Slider Hero Plugin
Summary
by MITRE • 07/12/2023
The Slider Hero plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 8.2.0. This is due to missing or incorrect nonce validation on the qc_slider_hero_duplicate() function. This makes it possible for unauthenticated attackers to duplicate slides via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 07/30/2023
The Slider Hero plugin for WordPress represents a widely used tool for creating dynamic slider interfaces on websites, with version 8.2.0 containing a critical cross-site request forgery vulnerability that affects numerous WordPress installations. This vulnerability stems from inadequate security controls within the plugin's duplicate functionality, specifically within the qc_slider_hero_duplicate() function that fails to properly validate nonce tokens. The absence of proper nonce validation creates a pathway for malicious actors to exploit the plugin's administrative features without authentication, potentially allowing them to manipulate slider content and compromise website integrity. This vulnerability directly impacts the plugin's security model by removing the essential authentication layer that should prevent unauthorized modifications to slider configurations.
The technical flaw manifests through the exploitation of the missing nonce validation mechanism that should normally verify the authenticity of administrative requests. When an administrator performs actions within the WordPress admin panel, legitimate requests include a unique nonce token that confirms the request originated from an authorized user with appropriate privileges. However, the Slider Hero plugin fails to implement this verification process for the duplicate function, allowing attackers to craft malicious requests that appear legitimate to the WordPress system. This weakness enables attackers to manipulate the slider content through forged requests that exploit the trust relationship between the browser and the WordPress admin interface, creating a dangerous scenario where any administrator can be tricked into executing unauthorized actions.
The operational impact of this vulnerability extends beyond simple content manipulation, potentially allowing attackers to disrupt website functionality, inject malicious content, or even establish persistent backdoors through the slider configuration modifications. An attacker could duplicate slides with malicious code, modify existing slide content to redirect users to phishing sites, or alter the slider's behavior to compromise user experience and security. The vulnerability's exploitation requires minimal technical skill since it relies on social engineering to trick administrators into clicking malicious links, making it particularly dangerous for websites where administrators frequently interact with external content or receive suspicious emails. This creates a significant risk for businesses relying on WordPress for their online presence, as the vulnerability can lead to data compromise, reputational damage, and potential regulatory violations.
Organizations should immediately update to patched versions of the Slider Hero plugin to address this vulnerability, as the security patch typically includes proper nonce validation implementation that aligns with WordPress security best practices. Additionally, administrators should implement network monitoring to detect suspicious activities related to slider modifications and consider implementing additional security layers such as web application firewalls to protect against CSRF attacks. The vulnerability demonstrates the importance of proper input validation and authentication mechanisms, aligning with CWE-352 which specifically addresses cross-site request forgery vulnerabilities in web applications. This case also reflects ATT&CK technique T1566 which covers social engineering tactics used to manipulate administrators into performing unwanted actions, highlighting how seemingly minor security flaws can create significant attack vectors in web applications.