CVE-2017-18634 in newspaper Theme
Summary
by MITRE
The newspaper theme before 6.7.2 for WordPress has script injection via td_ads[header] to admin-ajax.php.
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Analysis
by VulDB Data Team • 12/25/2023
The vulnerability identified as CVE-2017-18634 affects the newspaper theme for WordPress versions prior to 6.7.2, presenting a critical security flaw that enables unauthorized script injection attacks. This vulnerability specifically targets the admin-ajax.php endpoint within the WordPress administration interface, creating a pathway for malicious actors to execute arbitrary code on vulnerable systems. The flaw resides in how the theme handles the td_ads[header] parameter, which is processed through the admin-ajax.php handler without adequate input validation or sanitization measures.
The technical implementation of this vulnerability stems from insufficient parameter validation within the theme's advertising management system. When the td_ads[header] parameter is submitted to admin-ajax.php, the theme fails to properly sanitize or escape the input before processing it within the WordPress environment. This creates a classic cross-site scripting vulnerability that can be exploited by attackers to inject malicious JavaScript code into the admin interface. The vulnerability operates at the application layer and can be classified under CWE-79 as a cross-site scripting flaw, specifically in the context of WordPress theme implementations.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with potential access to administrative functions within the WordPress environment. Successful exploitation could allow threat actors to execute arbitrary code with the privileges of the web server, potentially leading to complete system compromise. Attackers could leverage this vulnerability to install backdoors, modify content, steal user credentials, or perform other malicious activities that would be difficult to detect. The attack surface is particularly concerning because it targets the admin-ajax.php endpoint, which is commonly used for legitimate administrative functions, making malicious activity harder to distinguish from normal operations.
The vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to command and control through web shell deployment and privilege escalation. Attackers could use this flaw to establish persistent access to the compromised WordPress installation, potentially using the administrative interface to further compromise the broader network infrastructure. The vulnerability also demonstrates characteristics of privilege escalation attacks, as it allows unauthorized code execution within the administrative context. Organizations using vulnerable versions of the newspaper theme should immediately implement mitigation strategies including updating to version 6.7.2 or later, implementing proper input validation measures, and monitoring for suspicious activity in the admin-ajax.php endpoint.
Mitigation strategies for this vulnerability should include immediate patching of the newspaper theme to version 6.7.2 or higher, which contains the necessary security fixes. Additionally, organizations should implement web application firewall rules to monitor and block suspicious requests to the admin-ajax.php endpoint, particularly those containing unusual parameter values. Input validation should be strengthened at the application level to ensure that all parameters passed to admin-ajax.php are properly sanitized before processing. Security monitoring should be enhanced to detect anomalous behavior in the admin interface, and access controls should be reviewed to ensure that only authorized users can submit advertising parameters. The vulnerability serves as a reminder of the importance of proper input validation and sanitization in web applications, particularly when dealing with user-supplied data that may be processed through administrative functions.