CVE-2007-3240 in WordPress
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in 404.php in the Vistered-Little theme for WordPress allows remote attackers to inject arbitrary web script or HTML via the URI (REQUEST_URI) that accesses index.php. NOTE: this can be leveraged for PHP code execution in an administrative session.
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Analysis
by VulDB Data Team • 09/04/2018
The vulnerability identified as CVE-2007-3240 represents a critical cross-site scripting flaw within the Vistered-Little WordPress theme, specifically affecting the 404.php file. This vulnerability resides in the handling of the REQUEST_URI parameter when users access index.php through malformed or crafted URI requests. The flaw stems from inadequate input validation and output sanitization mechanisms that fail to properly escape or filter user-supplied data before it is rendered in web pages. According to CWE-79, this vulnerability directly maps to improper neutralization of input during web page generation, making it a classic example of a client-side attack vector that can be exploited to compromise user sessions and potentially escalate privileges.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious URI request that gets processed by the vulnerable 404.php script. The REQUEST_URI parameter, which contains the full URI path of the requested resource, is not adequately sanitized before being included in the page output. When this unsanitized data is rendered in the browser context, it allows attackers to inject arbitrary HTML content and JavaScript code. The vulnerability's severity is amplified by its potential to be leveraged for PHP code execution within administrative sessions, as noted in the original description. This escalation capability suggests that attackers could potentially gain administrative privileges or execute commands on the affected WordPress installation.
From an operational perspective, this vulnerability presents significant risk to WordPress installations using the Vistered-Little theme, particularly those with administrative users who might inadvertently click on malicious links or visit compromised websites. The attack vector is relatively straightforward, requiring only that users navigate to a specially crafted URL that triggers the vulnerable 404.php script. The impact extends beyond simple XSS attacks as the potential for PHP code execution in administrative sessions creates opportunities for complete system compromise. This vulnerability aligns with ATT&CK technique T1059.007 for scripting and T1566.001 for spearphishing via web applications, demonstrating how initial access through web-based attacks can escalate to more serious compromise scenarios.
Mitigation strategies for this vulnerability should focus on immediate patching of the affected theme files, implementing proper input validation and output encoding mechanisms, and establishing comprehensive web application firewall rules to detect and block malicious URI patterns. Organizations should also consider implementing Content Security Policy headers to prevent execution of unauthorized scripts and ensure that all user-supplied input is properly sanitized before processing. The vulnerability highlights the importance of theme security auditing and the need for developers to follow secure coding practices, particularly regarding input validation and output encoding. Regular security assessments and monitoring of web application logs for suspicious URI patterns can help detect exploitation attempts and prevent successful attacks. Additionally, user education regarding the risks of clicking on untrusted links remains critical in preventing successful exploitation of such vulnerabilities.