CVE-2016-10926 in nelio-ab-testing Plugin
Summary
by MITRE
The nelio-ab-testing plugin before 4.5.9 for WordPress has SSRF in ajax/iesupport.php.
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Analysis
by VulDB Data Team • 12/01/2023
The vulnerability identified as CVE-2016-10926 affects the nelio-ab-testing plugin for WordPress, specifically versions prior to 4.5.9, and represents a server-side request forgery flaw that can be exploited to manipulate server-side requests. This vulnerability resides within the ajax/iesupport.php file, which is part of the plugin's functionality for handling asynchronous requests related to Internet Explorer support testing. The flaw allows an attacker to manipulate the plugin's behavior by crafting malicious requests that can cause the server to make unintended requests to internal or external systems, potentially leading to unauthorized access to internal resources or data exfiltration.
The technical implementation of this SSRF vulnerability stems from insufficient input validation and sanitization within the ajax/iesupport.php endpoint. When the plugin processes requests through this file, it fails to properly validate or sanitize user-supplied parameters that are used to construct URLs for making additional HTTP requests. This allows an attacker to inject malicious URLs or IP addresses that the server will then attempt to access on behalf of the vulnerable WordPress installation. The vulnerability is particularly concerning because it operates at the server level, meaning that an attacker could potentially access internal network resources that would normally be protected by firewalls or network segmentation, as the WordPress server itself becomes a conduit for making requests to internal systems.
The operational impact of this vulnerability extends beyond simple data theft or unauthorized access to include potential escalation to more severe attacks within the compromised environment. An attacker could leverage this SSRF vulnerability to probe internal network services, potentially discovering additional vulnerable systems or applications that are not directly exposed to the internet. This reconnaissance capability can lead to further exploitation opportunities, as demonstrated by the ATT&CK framework's technique T1016 for system network configuration discovery and T1046 for network service scanning. The vulnerability also aligns with CWE-918, which specifically addresses server-side request forgery, and can be categorized under CWE-20 for improper input validation. Organizations running vulnerable versions of the nelio-ab-testing plugin face significant risk of unauthorized access to their internal systems, especially in environments where WordPress installations are hosted in shared or managed hosting environments where internal network boundaries may be less strictly enforced.
Mitigation strategies for this vulnerability involve immediate patching of the nelio-ab-testing plugin to version 4.5.9 or later, which contains the necessary fixes to properly validate and sanitize input parameters before they are used in constructing server-side requests. Additionally, administrators should implement network-level controls such as firewalls and network access control lists to restrict outbound connections from the WordPress server to internal systems, particularly blocking connections to common internal ports and services. The implementation of web application firewalls can also provide an additional layer of protection by monitoring and filtering requests to the vulnerable endpoint. Organizations should also consider implementing principle of least privilege access controls, ensuring that the WordPress server has minimal necessary permissions and network access to prevent lateral movement if the vulnerability is exploited. Regular security audits and vulnerability assessments should include checks for outdated plugins and themes, as this vulnerability demonstrates how seemingly minor flaws in third-party components can create significant security risks for entire WordPress installations.