CVE-2015-7357 in uDesign Theme
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the uDesign (aka U-Design) theme 2.3.0 before 2.7.10 for WordPress allows remote attackers to inject arbitrary web script or HTML via a fragment identifier, as demonstrated by #<svg onload=alert(1)>.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/30/2022
The CVE-2015-7357 vulnerability represents a critical cross-site scripting flaw discovered in the uDesign WordPress theme version 2.3.0 through 2.7.9. This vulnerability specifically targets the theme's handling of fragment identifiers within URL parameters, creating an exploitable vector that enables remote attackers to inject malicious web scripts or HTML content. The flaw operates by leveraging the fragment identifier component of URLs, which typically begins with the hash symbol (#) and is often used for client-side navigation within web pages. In this case, the vulnerability manifests when the theme fails to properly sanitize or escape fragment identifiers before rendering them in the browser context, allowing attackers to inject SVG elements with onload events that execute arbitrary JavaScript code.
The technical exploitation of this vulnerability follows a well-established XSS attack pattern where the malicious payload #<svg onload=alert(1)> demonstrates how an attacker can embed an SVG element with an onload event handler that triggers when the page loads. This particular payload executes an alert function that displays a message box, but the attack vector is significantly more dangerous in practice as it could be modified to perform more severe actions such as stealing session cookies, redirecting users to malicious sites, or executing persistent XSS attacks that compromise user accounts. The vulnerability resides in the theme's failure to implement proper input validation and output encoding for fragment identifiers, which is a fundamental security principle in web application development. This weakness aligns with CWE-79, which defines Cross-Site Scripting as the insertion of malicious code into web pages viewed by other users, and demonstrates poor secure coding practices that violate core web security guidelines.
The operational impact of CVE-2015-7357 extends beyond simple script injection, as it creates persistent security risks for WordPress sites using the affected uDesign theme. When exploited, this vulnerability can compromise user sessions, enable credential theft, and potentially allow attackers to gain unauthorized administrative access to compromised sites. The vulnerability affects not just individual users but entire WordPress installations that rely on the uDesign theme, making it particularly dangerous for businesses and organizations that depend on WordPress for their web presence. The exploitation requires minimal technical skill from attackers, as the payload can be delivered through simple URL manipulation, making it an attractive target for automated attacks. This vulnerability also demonstrates the broader risk associated with theme and plugin vulnerabilities in WordPress ecosystems, where third-party components can introduce security weaknesses that affect thousands of sites simultaneously.
Mitigation strategies for CVE-2015-7357 require immediate action to upgrade the uDesign theme to version 2.7.10 or later, which contains the necessary patches to address the fragment identifier sanitization issue. System administrators should also implement additional security measures such as Content Security Policy headers to limit script execution, regular security audits of installed themes and plugins, and monitoring for suspicious URL patterns that might indicate exploitation attempts. The vulnerability highlights the importance of proper input validation and output encoding practices, which align with ATT&CK technique T1213.002 for credential access and T1566.001 for credential harvesting through social engineering. Organizations should also consider implementing web application firewalls to detect and block malicious fragment identifier patterns, and establish regular patch management processes to ensure timely updates of all WordPress components. The incident underscores the critical need for comprehensive security testing of third-party WordPress themes and plugins, as well as the importance of maintaining up-to-date security practices that prevent exploitation of known vulnerabilities.