CVE-2017-6540 in webpagetest
Summary
by MITRE
Multiple Cross-Site Scripting (XSS) issues were discovered in webpagetest 3.0. The vulnerabilities exist due to insufficient filtration of user-supplied data (configs) passed to the webpagetest-master/www/benchmarks/compare.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 • 09/05/2020
The vulnerability identified as CVE-2017-6540 represents a critical cross-site scripting flaw in webpagetest version 3.0, specifically within the benchmark comparison functionality. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data, creating a persistent security gap that allows malicious actors to inject arbitrary code into web applications. The vulnerability is particularly concerning as it affects the compare.php endpoint located at webpagetest-master/www/benchmarks/compare.php, which serves as a central point for comparing web performance metrics and benchmark results.
The technical exploitation of this vulnerability occurs through the improper handling of configuration parameters that are passed to the comparison interface. When users submit benchmark configurations or performance test parameters, the application fails to implement adequate sanitization measures before rendering these inputs within the web page context. This insufficient filtration creates an environment where malicious scripts can be executed directly within the browser of legitimate users who access the vulnerable application. The flaw operates under the common CWE-79 category of Cross-Site Scripting, specifically manifesting as a reflected XSS vulnerability where attacker-controlled data flows directly from user input to the browser without proper encoding or validation.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the ability to manipulate web content, steal user sessions, and potentially redirect users to malicious websites. In the context of webpagetest, which is commonly used for performance monitoring and benchmarking across various web applications, this vulnerability could be exploited to compromise the integrity of performance data or to gain unauthorized access to sensitive testing configurations. The attack surface is particularly dangerous because webpagetest is often used in enterprise environments where performance testing data may contain confidential information about web application behavior, user traffic patterns, and system performance metrics.
Security professionals should consider this vulnerability in relation to the ATT&CK framework's TA0001 Initial Access and TA0002 Execution phases, as it provides a straightforward method for attackers to establish a foothold within web application environments. The vulnerability's classification under CWE-79 aligns with the broader category of input validation failures that have historically accounted for a significant portion of web application security incidents. Organizations utilizing webpagetest version 3.0 should implement immediate mitigations including input sanitization, output encoding, and proper content security policies to prevent the execution of malicious scripts. The recommended remediation strategy involves implementing strict validation of all user-supplied inputs, applying proper HTML escaping techniques, and deploying web application firewalls to detect and prevent XSS attack patterns. Additionally, regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other components of the web application ecosystem.