CVE-2019-16221 in WordPress
Summary
by MITRE
WordPress before 5.2.3 allows reflected XSS in the dashboard.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/19/2023
WordPress versions prior to 5.2.3 contained a reflected cross-site scripting vulnerability that allowed attackers to inject malicious scripts into the dashboard interface. This vulnerability originated from insufficient input validation and output escaping mechanisms within the WordPress admin dashboard, specifically affecting how the application handled user-supplied data in URL parameters. The flaw enabled malicious actors to craft specially crafted URLs that, when visited by authenticated administrators, would execute arbitrary JavaScript code in the victim's browser context. This reflected XSS vulnerability was particularly dangerous because it targeted the privileged dashboard environment where administrators performed critical system management tasks. The vulnerability could be exploited through various attack vectors including malicious links sent via email or social engineering tactics, where unsuspecting administrators would click on compromised URLs. When executed, the malicious scripts could steal administrator session cookies, perform unauthorized actions on behalf of the user, or redirect victims to phishing sites. The vulnerability was classified under CWE-79 as a failure to sanitize user input before reflecting it back to the browser, and it aligned with ATT&CK technique T1059.007 for command and scripting interpreter. The impact extended beyond simple data theft as attackers could potentially escalate privileges, modify content, or establish persistent access through the compromised administrative session. The vulnerability affected WordPress installations that had not yet been updated to version 5.2.3, which included necessary patches to properly escape and validate input parameters before rendering them in the dashboard interface.
The technical exploitation of this vulnerability required minimal prerequisites and could be executed against any WordPress installation running versions earlier than 5.2.3. Attackers typically constructed malicious URLs containing encoded JavaScript payloads that would be reflected back to the browser when the admin user accessed the dashboard. The reflected nature of the vulnerability meant that the malicious script was not stored on the server but rather executed immediately upon page load, making it difficult to detect through traditional server-side logging. The vulnerability was particularly concerning because WordPress administrators often had elevated privileges and access to sensitive system information, making successful exploitation a significant security risk. The attack vector specifically targeted the admin dashboard where users would typically have active sessions, increasing the likelihood of successful exploitation. The vulnerability was consistent with common web application security flaws identified in the OWASP Top 10, particularly the identification of cross-site scripting as a persistent threat to web application security. The patch implemented in WordPress 5.2.3 addressed the issue by strengthening input validation and ensuring proper output escaping mechanisms were applied to all user-supplied parameters before rendering them in the dashboard context.
Mitigation strategies for this vulnerability involved immediate upgrading to WordPress version 5.2.3 or later, which contained the necessary security patches to prevent reflected XSS attacks. Organizations should have implemented robust patch management processes to ensure timely deployment of security updates across all WordPress installations. Additional defensive measures included implementing content security policies to limit script execution, monitoring for suspicious URL patterns in web server logs, and educating administrators about phishing risks and social engineering attacks. The vulnerability highlighted the importance of maintaining current security patches and following secure coding practices that prevent user input from being directly reflected in web pages without proper sanitization. Security teams should have established automated monitoring systems to detect attempts to exploit known vulnerabilities, particularly those affecting high-privilege administrative interfaces. The incident underscored the critical nature of defending administrative access points and implementing layered security controls that protect against both automated attacks and targeted exploitation attempts. Organizations that had not yet updated their WordPress installations were particularly vulnerable to this attack vector, as the reflected XSS could be leveraged to establish persistent access to administrative accounts. The vulnerability also demonstrated the necessity of regular security assessments and vulnerability scanning to identify and remediate similar issues before they could be exploited by malicious actors.