CVE-2018-18726 in YUNUCMS
Summary
by MITRE
An XSS issue was discovered in admin/sitelink/editsitelink?id=16 in YUNUCMS 1.1.5.
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Analysis
by VulDB Data Team • 04/07/2020
The vulnerability identified as CVE-2018-18726 represents a cross-site scripting flaw within the YUNUCMS content management system version 1.1.5. This issue specifically manifests in the administrative interface at the path admin/sitelink/editsitelink?id=16, where user input is not properly sanitized before being rendered back to the browser. The vulnerability falls under the category of CWE-79 - Improper Neutralization of Input During Web Page Generation, which is a fundamental weakness in web application security that allows attackers to inject malicious scripts into web pages viewed by other users. The flaw exists in the parameter handling mechanism of the site link editing functionality, where an attacker can manipulate the id parameter to inject malicious JavaScript code that will execute in the context of other administrators or users who access the affected page. This particular vulnerability is classified as a reflected cross-site scripting attack since the malicious payload is reflected back to the user through the application's response without being stored on the server.
The operational impact of this vulnerability is significant as it provides attackers with the ability to escalate privileges within the CMS administrative environment. An attacker who successfully exploits this vulnerability can execute arbitrary JavaScript code in the browser of authenticated administrators, potentially leading to complete compromise of the CMS instance. The attack vector requires minimal user interaction since the vulnerability is present in the administrative interface, meaning that if an administrator clicks on a malicious link or visits a compromised page, the injected script will execute in their browser session. This could result in session hijacking, privilege escalation, data theft, or even the complete takeover of the CMS administrative account. The vulnerability also aligns with ATT&CK technique T1059.007 - Command and Scripting Interpreter: JavaScript, as it leverages JavaScript execution capabilities within the browser to perform malicious activities. The reflected nature of the vulnerability means that attackers can craft specific URLs that, when visited by administrators, will automatically execute the malicious payload without requiring any persistent storage on the server.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and output encoding mechanisms throughout the application. The primary fix involves sanitizing all user-supplied input parameters, particularly those used in dynamic page generation, before they are rendered back to the browser. This includes implementing proper HTML entity encoding for all dynamic content and employing Content Security Policy (CSP) headers to limit the execution of inline scripts. Organizations should also consider implementing input validation at multiple layers including the application firewall, web application firewall, and application code level. The recommended remediation includes upgrading to a patched version of YUNUCMS 1.1.5, as the vulnerability has been addressed in subsequent releases. Additionally, implementing proper access controls and monitoring for administrative interfaces can help detect and prevent exploitation attempts. Security teams should also conduct regular security assessments and penetration testing to identify similar vulnerabilities in other components of the web application. The vulnerability demonstrates the importance of following secure coding practices and adhering to the principle of least privilege, where administrative interfaces should be protected against any form of injection attacks that could compromise the integrity of the entire system. Organizations should also implement regular security training for developers to prevent similar issues in future software development cycles.