CVE-2007-1049 in WordPress
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the wp_explain_nonce function in the nonce AYS functionality (wp-includes/functions.php) for WordPress 2.0 before 2.0.9 and 2.1 before 2.1.1 allows remote attackers to inject arbitrary web script or HTML via the file parameter to wp-admin/templates.php, and possibly other vectors involving the action variable.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/13/2021
The CVE-2007-1049 vulnerability represents a critical cross-site scripting flaw in WordPress core functionality that emerged during the 2.0.x release cycle. This vulnerability specifically targets the wp_explain_nonce function within the nonce AYS (Are You Sure) functionality located in wp-includes/functions.php. The flaw manifests when the system fails to properly sanitize user input parameters, particularly the file parameter in wp-admin/templates.php and the action variable in other vectors. This vulnerability exists in WordPress versions 2.0 before 2.0.9 and 2.1 before 2.1.1, indicating a significant window of exposure for affected installations. The vulnerability operates under the CWE-79 principle of Cross-Site Scripting, where malicious scripts can be injected into web applications through unvalidated input fields. The attack vector involves remote exploitation where an attacker can inject arbitrary web script or HTML code, potentially compromising user sessions and enabling further malicious activities.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within WordPress's nonce handling system. When the wp_explain_nonce function processes the file parameter in wp-admin/templates.php, it does not properly sanitize or escape the input before rendering it in the web page context. This allows attackers to inject malicious payloads that execute in the context of other users' browsers who visit affected pages. The vulnerability extends beyond just the templates.php file to include other vectors involving the action variable, suggesting a broader scope in the affected WordPress functionality. The flaw essentially creates a pathway for persistent script injection where malicious code can be executed in the browser of unsuspecting users, potentially leading to session hijacking, credential theft, or redirection to malicious sites. This represents a classic XSS vulnerability that aligns with ATT&CK technique T1531 for 'Modify Existing Service' and T1059.001 for 'Command and Scripting Interpreter' through web-based payloads.
The operational impact of CVE-2007-1049 is severe for WordPress installations that remain vulnerable, as it enables attackers to compromise user sessions and potentially gain unauthorized access to administrative functions. When exploited, this vulnerability can allow attackers to execute malicious scripts that may steal cookies, redirect users to phishing sites, or perform actions on behalf of authenticated users. The attack typically requires no special privileges beyond access to the vulnerable WordPress installation, making it particularly dangerous for widely used content management systems. Organizations running vulnerable WordPress versions face significant risk of data breaches, service disruption, and potential compromise of their entire web presence. The vulnerability's persistence across multiple minor versions indicates that it was not quickly addressed, leaving many installations exposed for extended periods. The impact extends beyond individual site compromise to potentially affect entire user bases, especially in scenarios where administrators or users with elevated privileges are targeted. This vulnerability demonstrates the critical importance of timely patch management and input validation in web application security, as it represents a fundamental flaw in how WordPress handled nonce verification and input sanitization.
The remediation strategy for CVE-2007-1049 involves immediate upgrade to WordPress versions 2.0.9 or 2.1.1, which contain the necessary patches to address the XSS vulnerability in the nonce functionality. System administrators should prioritize patching their WordPress installations and verify that the upgrade has successfully resolved the vulnerability through testing. Additional mitigations include implementing proper input validation at multiple layers of the application, including output encoding for all dynamic content, and regular security audits of WordPress installations. Organizations should also consider implementing web application firewalls to detect and block suspicious input patterns, though this should not replace proper patching. The vulnerability serves as a reminder of the importance of following security best practices such as principle of least privilege, input validation, and regular security updates. Security teams should conduct vulnerability assessments to identify other potential XSS vulnerabilities in their WordPress installations and related applications, as the same root cause patterns may exist elsewhere in the codebase. The incident underscores the necessity of maintaining current security practices and the critical role that timely patch management plays in protecting web applications from known vulnerabilities.