CVE-2016-11005 in instalinker Plugin
Summary
by MITRE
The instalinker plugin before 1.1.2 for WordPress has includes/instalinker-admin-preview.php?client_id= XSS.
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Analysis
by VulDB Data Team • 12/26/2023
The vulnerability identified as CVE-2016-11005 affects the instalinker plugin version 1.1.1 and earlier for WordPress platforms, representing a cross-site scripting weakness that could enable attackers to execute malicious scripts within the context of a victim's browser. This vulnerability specifically resides in the includes/instalinker-admin-preview.php file where the client_id parameter is improperly handled, creating an opportunity for malicious input to be injected and executed without proper sanitization or validation. The issue stems from the plugin's failure to adequately filter user-supplied input before incorporating it into dynamic web content, allowing attackers to manipulate the client_id parameter and inject malicious code that would execute in the browsers of unsuspecting users who view the affected administrative preview functionality.
The technical flaw manifests as a classic reflected cross-site scripting vulnerability where the client_id parameter is directly included in the page output without appropriate output encoding or sanitization measures. This allows an attacker to craft a malicious URL containing script code within the client_id parameter, which when accessed by an authenticated administrator or user with sufficient privileges, would execute the injected payload in their browser context. The vulnerability operates under CWE-79 which categorizes cross-site scripting flaws as weaknesses that allow attackers to inject client-side scripts into web applications. The impact is particularly concerning given that this affects an administrative preview functionality, meaning that successful exploitation could potentially allow attackers to escalate privileges or perform actions within the WordPress administration interface.
The operational impact of this vulnerability extends beyond simple script injection, as it could enable attackers to perform a range of malicious activities including session hijacking, credential theft, or even complete compromise of administrative accounts. When an administrator accesses the malicious preview page, the injected JavaScript code would execute in their browser with the privileges of that administrator, potentially allowing for unauthorized modifications to the WordPress installation, data exfiltration, or deployment of additional malware. This vulnerability aligns with ATT&CK technique T1566 which covers social engineering tactics, as attackers could craft malicious links that appear legitimate to administrators, and T1059 which involves command and control through various execution methods. The risk is amplified because the vulnerability requires minimal user interaction beyond viewing the malicious preview page, making it particularly dangerous in environments where administrators frequently access preview functionality.
Mitigation strategies for this vulnerability should focus on immediate plugin updates to version 1.1.2 or later where the XSS flaw has been addressed through proper input sanitization and output encoding. System administrators should implement comprehensive security monitoring to detect any suspicious activities related to the instalinker plugin and ensure that all WordPress installations maintain current versions of plugins and core software. Additionally, implementing proper input validation and output encoding practices, such as using WordPress's built-in sanitization functions and escaping output for different contexts, would prevent similar vulnerabilities from occurring in the future. The remediation process should also include reviewing other plugin files for similar patterns of insecure input handling and ensuring that all user-supplied data is properly validated before being incorporated into dynamic web content. Organizations should conduct regular security audits of their WordPress installations and maintain updated threat intelligence to identify and address similar vulnerabilities across their entire attack surface.