CVE-2018-8805 in Yxcms Building System
Summary
by MITRE
Yxcms building system (compatible cell phone) v1.4.7 has XSS via the content parameter to protected\apps\default\view\default\extend_guestbook.php or protected\apps\default\view\mobile\extend_guestbook.php in an index.php?r=default/column/index&col=guestbook request.
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Analysis
by VulDB Data Team • 01/15/2020
The vulnerability identified as CVE-2018-8805 affects the Yxcms building system version 1.4.7, specifically targeting the guestbook functionality within both desktop and mobile interface components. This issue represents a cross-site scripting vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. The vulnerability manifests when the content parameter is passed through the extend_guestbook.php file located in both the default and mobile view directories of the protected apps folder. The attack vector occurs through the index.php?r=default/column/index&col=guestbook request structure, which processes user input without proper sanitization or encoding mechanisms.
The technical flaw resides in the insufficient input validation and output encoding practices within the Yxcms system's guestbook module. When users submit content through the guestbook form, the system fails to properly sanitize the input data before rendering it in the web page context. This omission creates an environment where malicious actors can inject HTML or JavaScript code that executes in the browsers of other users who view the affected guestbook entries. The vulnerability affects both desktop and mobile interfaces, indicating a systemic issue within the application's input handling mechanisms rather than a localized problem within a single user interface component.
The operational impact of this vulnerability extends beyond simple data corruption or display issues, as it provides attackers with potential access to user sessions, cookies, and other sensitive information. An attacker could leverage this XSS flaw to steal user authentication tokens, redirect victims to malicious websites, or perform actions on behalf of authenticated users. The vulnerability affects the entire guestbook functionality across both interface variants, potentially compromising user data integrity and system security. Given that guestbook modules often collect user-submitted content that may include personal information, the risk of data exposure increases significantly when such modules are vulnerable to cross-site scripting attacks.
Security professionals should note that this vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications. The attack pattern follows typical XSS exploitation methodologies where unfiltered user input is directly rendered in web pages without proper HTML escaping or context-appropriate encoding. Organizations utilizing Yxcms v1.4.7 should implement immediate mitigations including input sanitization, output encoding, and the implementation of Content Security Policy headers to prevent script execution. Additionally, this vulnerability demonstrates the importance of consistent security practices across all application components, as both desktop and mobile interfaces exhibit the same flaw, suggesting a lack of comprehensive input validation throughout the system architecture.
The remediation approach should involve updating the Yxcms system to a patched version that properly sanitizes user input before rendering it in web contexts. Developers should implement proper HTML entity encoding for all user-supplied content, utilize secure coding practices for input validation, and consider implementing a Web Application Firewall to provide additional protection layers. Organizations should also conduct thorough security assessments of their web applications to identify similar vulnerabilities in other modules, as the presence of one XSS vulnerability often indicates potential issues in other input handling components. The vulnerability serves as a reminder of the critical importance of maintaining current security patches and implementing robust input validation mechanisms across all web application components, particularly those that process user-submitted data.