CVE-2007-2627 in WordPress
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in sidebar.php in WordPress, when custom 404 pages that call get_sidebar are used, allows remote attackers to inject arbitrary web script or HTML via the query string (PHP_SELF), a different vulnerability than CVE-2007-1622.
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Analysis
by VulDB Data Team • 03/12/2017
The vulnerability described in CVE-2007-2627 represents a classic cross-site scripting flaw within the WordPress content management system that specifically affects the sidebar.php template file. This issue manifests when custom 404 error pages are implemented and utilize the get_sidebar() function, creating a pathway for malicious actors to execute arbitrary web scripts or HTML code within the context of affected user sessions. The vulnerability operates through the PHP_SELF variable in the query string, which serves as an injection vector for cross-site scripting attacks.
The technical mechanism behind this vulnerability stems from improper input sanitization within WordPress's template processing system. When a custom 404 page is rendered and calls get_sidebar(), the system fails to adequately escape or filter the PHP_SELF variable that contains user-supplied input from the query string. This oversight creates an environment where attacker-controlled data can be directly embedded into the webpage output without proper validation or sanitization. The flaw specifically affects the sidebar rendering process, making it particularly dangerous as sidebar components often appear across multiple pages and user contexts, amplifying the potential impact of successful exploitation.
From an operational perspective, this vulnerability presents significant security risks to WordPress installations that utilize custom 404 pages with sidebar functionality. Attackers can craft malicious URLs containing script payloads that, when accessed by unsuspecting users, execute in the victim's browser context. The attack surface is particularly concerning because 404 error pages are frequently accessed by various automated tools including web crawlers, search engines, and potentially malicious actors scanning for vulnerabilities. This makes the exploitation vector more accessible and the potential for widespread impact greater. The vulnerability differs from CVE-2007-1622 in its specific implementation and attack vector, though both represent XSS weaknesses within WordPress's core functionality.
The security implications extend beyond simple script execution as this vulnerability can enable more sophisticated attacks such as session hijacking, credential theft, or redirection to malicious sites. According to CWE classification, this represents a CWE-79: Cross-site Scripting vulnerability where the weakness occurs in the output generation phase of the application. The attack pattern aligns with ATT&CK technique T1566.001 for initial access through malicious web content, and T1059.001 for command and control through script injection. Organizations using WordPress with custom 404 pages containing sidebar elements should prioritize immediate remediation to prevent exploitation. The recommended mitigation involves implementing proper input validation and output escaping mechanisms for all user-supplied data, particularly within template files that handle dynamic content. Additionally, WordPress administrators should ensure that all custom 404 pages properly sanitize input variables before rendering them in the output, and consider updating to patched versions of WordPress that address this specific vulnerability in the sidebar template processing.