CVE-2024-4381 in CB Plugin
Summary
by MITRE • 06/21/2024
The CB (legacy) WordPress plugin through 0.9.4.18 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)
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Analysis
by VulDB Data Team • 03/22/2025
The vulnerability identified as CVE-2024-4381 affects the CB legacy WordPress plugin version 0.9.4.18 and earlier, presenting a critical security risk through stored cross-site scripting vulnerabilities. This issue specifically targets high-privilege users including administrators who possess the capability to modify plugin settings, creating a dangerous attack vector that can persist across user sessions and potentially compromise multiple system components. The flaw arises from inadequate sanitization and escaping of user-provided input within the plugin's administrative interfaces, which allows malicious code to be stored and subsequently executed when other users access the affected pages.
The technical implementation of this vulnerability stems from the plugin's failure to properly validate and sanitize input parameters before storing them in the WordPress database. When administrators configure plugin settings or input data through the administrative interface, the plugin does not adequately filter or escape potentially malicious content such as javascript code, html tags, or other scriptable elements. This improper handling occurs even in environments where the unfiltered_html capability has been restricted, such as in multisite WordPress installations where security policies typically prevent high-privilege users from injecting raw html content. The vulnerability specifically manifests in the plugin's settings handling mechanisms, where user-supplied data flows directly into the output without proper context-aware escaping, creating persistent XSS opportunities.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers with administrator privileges to establish persistent backdoors, steal session cookies, redirect users to malicious sites, or manipulate administrative interfaces. In a multisite environment, this vulnerability becomes particularly dangerous as it can be leveraged to compromise multiple sites within the network, potentially leading to widespread data breaches or complete system takeovers. The stored nature of the XSS means that once an attacker successfully injects malicious code, it will execute automatically for any user who accesses the affected plugin interface or pages that display the stored content, making this a particularly insidious threat that can persist long after the initial compromise.
Security professionals should note that this vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and represents a variant of the more general CWE-20 category for input validation issues. From an ATT&CK framework perspective, this vulnerability maps to T1566.001 (Phishing: Spearphishing Attachment) and T1059.001 (Command and Scripting Interpreter: PowerShell) as attackers can leverage the XSS to deliver additional payloads or establish command execution capabilities. The vulnerability also relates to T1213.002 (Data from Information Repositories: Databases) as compromised administrative sessions can lead to unauthorized database access and data exfiltration. Organizations should implement immediate mitigations including upgrading to the latest plugin version, applying the vendor-supplied patch, and reviewing existing plugin configurations for any malicious code that may have been previously injected. Additionally, security monitoring should focus on detecting unauthorized administrative activities and anomalous plugin configuration changes that might indicate exploitation attempts.