CVE-2017-9066 in WordPress
Summary
by MITRE
In WordPress before 4.7.5, there is insufficient redirect validation in the HTTP class.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/06/2022
The vulnerability identified as CVE-2017-9066 represents a critical security flaw in WordPress versions prior to 4.7.5, specifically within the HTTP class implementation. This issue stems from inadequate validation of redirect URLs, creating a pathway for malicious actors to exploit the system through improper redirection mechanisms. The flaw exists in the core WordPress framework's handling of HTTP redirects, which are commonly used for authentication flows, API communications, and various web interactions. Attackers can leverage this vulnerability to manipulate redirect behavior and potentially direct users to malicious websites or execute unauthorized actions.
The technical implementation of this vulnerability resides in the WordPress HTTP class where redirect validation occurs. When the system processes HTTP redirects, it fails to properly sanitize or validate the target URLs, allowing attackers to inject malicious redirect destinations. This weakness enables what is commonly referred to as open redirect vulnerabilities, where the application accepts user-supplied input without adequate verification. The flaw specifically impacts how WordPress handles redirect parameters and URL validation during HTTP operations, making it possible for attackers to craft malicious URLs that bypass normal security checks. This issue directly relates to CWE-601, which categorizes open redirect vulnerabilities as a serious concern in web application security.
The operational impact of CVE-2017-9066 extends beyond simple redirection manipulation and can enable more sophisticated attack vectors. An attacker could potentially use this vulnerability to create phishing campaigns by redirecting users to malicious sites that appear legitimate, or to bypass security controls within WordPress installations. The vulnerability affects all WordPress installations running versions earlier than 4.7.5, making it particularly dangerous as it impacts a substantial portion of the WordPress ecosystem. This flaw could be exploited in conjunction with other attacks, such as cross-site scripting or credential theft attempts, amplifying the overall security risk to affected systems.
The mitigation strategy for this vulnerability requires immediate patching of WordPress installations to version 4.7.5 or later, where the redirect validation has been properly implemented. System administrators should prioritize updating their WordPress environments and verify that all plugins and themes are also compatible with the patched version. Security monitoring should include checking for unauthorized redirect patterns in web server logs and implementing proper URL validation mechanisms. Organizations should also consider implementing additional security controls such as web application firewalls that can detect and block suspicious redirect attempts. This vulnerability demonstrates the critical importance of proper input validation in web applications and aligns with ATT&CK technique T1566, which covers the use of social engineering through malicious redirects. The fix implemented in WordPress 4.7.5 addresses the core validation issues by ensuring that redirect URLs undergo proper sanitization and verification before being processed, thereby preventing attackers from exploiting this weakness to manipulate redirect behavior.