CVE-2006-0776 in guestex
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in guestex.pl in Teca Scripts Guestex 1.0 allows remote attackers to inject arbitrary web script or HTML via the url parameter.
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Analysis
by VulDB Data Team • 08/26/2017
The vulnerability identified as CVE-2006-0776 represents a classic cross-site scripting flaw in the Teca Scripts Guestex 1.0 web application. This security weakness resides in the guestex.pl script which fails to properly sanitize user input before incorporating it into web page responses. The specific vector of attack occurs through the url parameter, which serves as an entry point for malicious actors to inject arbitrary web scripts or HTML content. This type of vulnerability falls under the Common Weakness Enumeration category CWE-79, which specifically addresses improper neutralization of input during web page generation, commonly known as cross-site scripting. The flaw demonstrates a fundamental failure in input validation and output encoding practices that are critical for web application security.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with the capability to execute malicious code within the context of other users' browsers. When a victim visits a page containing the malicious script injection, the code executes in their browser session, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability's remote exploitability means that attackers do not require physical access or local network privileges to leverage this weakness. This characteristic aligns with the MITRE ATT&CK framework's technique T1566, which covers the execution of malicious code through web-based attacks, and specifically targets the credential access and persistence phases of an attack lifecycle.
The technical exploitation of this vulnerability requires minimal sophistication, as it relies on the web application's failure to properly validate or escape user-provided input. Attackers can craft malicious URLs containing script tags or other HTML elements that get executed when the vulnerable application processes the url parameter. The absence of proper input sanitization mechanisms in the guestex.pl script creates an environment where untrusted data flows directly into web page output without adequate protection. This vulnerability demonstrates the critical importance of implementing proper input validation and output encoding as defensive measures against XSS attacks, which should be considered fundamental security controls in all web application development processes.
Organizations utilizing Teca Scripts Guestex 1.0 should implement immediate mitigations including input validation that filters or escapes special characters in user-supplied parameters, particularly those used in URL construction. The recommended approach involves implementing proper output encoding mechanisms that prevent script execution in web contexts, ensuring that any user-provided content is treated as data rather than executable code. Additionally, implementing a Content Security Policy (CSP) header can provide an additional layer of protection by restricting the sources from which scripts can be loaded. The vulnerability serves as a reminder of the critical need for regular security assessments and the implementation of secure coding practices throughout the software development lifecycle. Organizations should also consider upgrading to newer versions of the software where these security flaws have been addressed through proper input validation and output encoding implementations.