CVE-2017-6537 in webpagetest
Summary
by MITRE
A Cross-Site Scripting (XSS) issue was discovered in webpagetest 3.0. The vulnerability exists due to insufficient filtration of user-supplied data (bgcolor) passed to the webpagetest-master/www/video/view.php URL. An attacker could execute arbitrary HTML and script code in a browser in the context of the vulnerable website.
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Analysis
by VulDB Data Team • 02/13/2026
The vulnerability identified as CVE-2017-6537 represents a critical cross-site scripting flaw in the webpagetest 3.0 application, specifically within the video viewing component. This vulnerability stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data, creating an exploitable entry point for malicious actors. The affected component resides in the webpagetest-master/www/video/view.php file where the bgcolor parameter is processed without sufficient security measures to prevent code injection attacks.
The technical nature of this vulnerability aligns with CWE-79, which categorizes cross-site scripting as a weakness where untrusted data is improperly incorporated into web pages without adequate validation or encoding. The flaw manifests when the application accepts the bgcolor parameter through the URL and directly incorporates it into the HTML output without proper sanitization or context-appropriate encoding. This allows attackers to inject malicious scripts that execute within the browser context of legitimate users interacting with the vulnerable application.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to potentially steal session cookies, perform unauthorized actions on behalf of users, or redirect victims to malicious websites. The vulnerability affects the integrity of the web application's output and can compromise user privacy and security. Attackers can leverage this flaw to create persistent XSS payloads that remain active until the page is refreshed or the session ends, making it particularly dangerous for applications handling sensitive user data.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms. The most effective approach involves sanitizing all user-supplied input through proper encoding before incorporating it into the HTML output, particularly using context-appropriate encoding such as HTML entity encoding for HTML content. Additionally, implementing a Content Security Policy (CSP) can provide an additional layer of protection by restricting the sources from which scripts can be executed. The fix should also include validating the bgcolor parameter against a whitelist of acceptable values or implementing strict type checking to prevent malicious code injection attempts. This vulnerability demonstrates the critical importance of secure coding practices and input validation in web applications, as highlighted by ATT&CK technique T1203 which covers exploitation of web application vulnerabilities for code execution and privilege escalation.