CVE-2021-42748 in Beaver Builder
Summary
by MITRE • 01/10/2022
In Beaver Builder through 2.5.0.3, attackers can bypass the visibility controls protection mechanism via the REST API.
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Analysis
by VulDB Data Team • 01/13/2022
The vulnerability CVE-2021-42748 affects the Beaver Builder plugin version 2.5.0.3 and earlier, representing a critical security flaw in the WordPress ecosystem that undermines access control mechanisms. This issue resides within the plugin's REST API implementation where unauthorized users can circumvent intended visibility protections. The vulnerability specifically targets the plugin's content visibility controls that are designed to restrict access to certain elements based on user roles and permissions. Attackers exploiting this weakness can gain access to content that should be restricted to specific user groups, potentially exposing sensitive data or administrative functions to unauthorized parties.
The technical flaw manifests in the REST API endpoint handling where the plugin fails to properly validate user permissions before serving content. This represents a classic authorization bypass vulnerability that falls under the CWE-863 category of "Incorrect Authorization" and aligns with ATT&CK technique T1078 for Valid Accounts and T1566 for Phishing. The vulnerability occurs because the API endpoints do not adequately verify whether the requesting user possesses the necessary privileges to access specific content segments, allowing malicious actors to craft requests that bypass normal access controls. The flaw essentially permits any authenticated user to access content that should be restricted to administrators or specific user roles, creating a significant escalation of privileges scenario.
The operational impact of this vulnerability is substantial as it allows attackers to potentially access sensitive content, administrative interfaces, or configuration data that should remain protected. This could lead to complete compromise of the WordPress site, especially when combined with other vulnerabilities or when the site contains confidential information. The attack surface extends beyond simple content exposure to include potential data exfiltration, site defacement, or further exploitation of the compromised platform. Organizations using affected versions of Beaver Builder are at risk of unauthorized access to their website content, user data, and potentially administrative controls, making this vulnerability particularly dangerous in enterprise environments where content visibility controls are critical for security.
Mitigation strategies should focus on immediate patching to version 2.5.0.4 or later where the vulnerability has been addressed. Administrators should also implement additional security measures including restricting API access through firewall rules, monitoring REST API endpoints for suspicious activity, and ensuring proper user role management. Network segmentation and API rate limiting can help reduce the impact if exploitation occurs. Security teams should conduct thorough audits of all WordPress plugins and themes to identify similar vulnerabilities, particularly those involving REST API implementations. The vulnerability underscores the importance of proper access control implementation in web applications and demonstrates how seemingly minor flaws in permission systems can create significant security risks. Organizations should also consider implementing web application firewalls and security monitoring solutions that can detect anomalous API access patterns indicative of exploitation attempts.