CVE-2024-1386 in MailerLite Plugin
Summary
by MITRE • 05/02/2024
The MailerLite – Signup forms (official) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcode(s) in versions 1.5.0 to 1.7.6 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 04/03/2025
The vulnerability identified as CVE-2024-1386 affects the MailerLite Signup forms plugin for WordPress, specifically targeting versions ranging from 1.5.0 through 1.7.6. This issue represents a critical security flaw that undermines the integrity of WordPress installations by enabling attackers to execute malicious scripts within the context of the affected plugin's functionality. The vulnerability manifests through the plugin's shortcode implementation, which fails to properly sanitize or escape user-supplied input parameters, creating an attack surface that can be exploited by malicious actors with contributor-level privileges or higher. The attack vector specifically leverages the plugin's handling of shortcode attributes, where insufficient validation allows attackers to inject malicious code that persists in the system and executes when legitimate users access affected pages.
The technical flaw underlying CVE-2024-1386 stems from inadequate input sanitization and output escaping mechanisms within the plugin's shortcode processing code. When administrators or users with contributor permissions create or modify shortcode parameters, the plugin fails to properly validate or escape the input data before storing or rendering it in web pages. This vulnerability directly maps to CWE-79, which describes Cross-Site Scripting (XSS) flaws that occur when untrusted data is improperly handled and executed within a web application. The stored nature of this vulnerability means that malicious scripts are not only executed during the injection phase but also persist in the system, making them particularly dangerous as they can affect multiple users over time. The vulnerability's impact is amplified by the fact that it requires only contributor-level permissions, which are often granted to trusted users within WordPress environments, making the attack surface more accessible than many other XSS vulnerabilities.
The operational impact of CVE-2024-1386 extends beyond simple script execution, potentially enabling attackers to perform a wide range of malicious activities including session hijacking, data theft, and privilege escalation within the compromised WordPress environment. When authenticated users with contributor-level permissions or higher access pages containing the injected scripts, the malicious code executes in their browser context, potentially allowing attackers to steal cookies, modify content, redirect users to malicious sites, or even gain access to additional administrative functions. This vulnerability can lead to complete compromise of WordPress installations, particularly in environments where contributors have access to plugin configuration interfaces or where multiple users with varying permission levels interact with the system. The persistent nature of stored XSS vulnerabilities means that the attack can continue to affect users long after the initial injection, making detection and remediation more challenging. Security professionals should note that this vulnerability aligns with ATT&CK technique T1566.002, which covers the use of malicious content in web applications, and represents a significant risk to organizations relying on WordPress for their content management infrastructure.
Mitigation strategies for CVE-2024-1386 should prioritize immediate plugin updates to versions that address the identified XSS vulnerability, as the vendor has likely released patches to resolve the sanitization and escaping issues. Organizations should implement comprehensive access control measures, ensuring that only trusted administrators have contributor-level permissions, and regularly audit user roles and capabilities within their WordPress installations. Security monitoring should include regular scanning for malicious scripts in plugin shortcode parameters, with particular attention to user-generated content that may contain injected XSS payloads. Network-based intrusion detection systems should be configured to monitor for suspicious script execution patterns, while endpoint security solutions should be deployed to detect and prevent malicious script execution. Additionally, implementing Content Security Policy (CSP) headers can provide an additional layer of protection against XSS attacks by restricting script execution sources. Organizations should also consider implementing input validation and output sanitization measures at the application level, ensuring that all user-supplied data is properly validated and escaped before being processed or rendered in web pages. Regular security audits and penetration testing should be conducted to identify and remediate similar vulnerabilities in other WordPress plugins and themes, as the attack surface for stored XSS vulnerabilities in content management systems remains significant.