CVE-2017-16904 in LvyeCMS
Summary
by MITRE
The Public tologin feature in admin.php in LvyeCMS through 3.1 allows XSS via a crafted username that is mishandled during later log viewing by an administrator.
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Analysis
by VulDB Data Team • 12/09/2019
The vulnerability identified as CVE-2017-16904 resides within the LvyeCMS content management system version 3.1 and earlier, specifically affecting the public tologin functionality implemented in the admin.php file. This issue represents a classic cross-site scripting vulnerability that exploits improper input validation and sanitization mechanisms within the administrative interface. The flaw enables attackers to inject malicious scripts through a specially crafted username parameter that gets processed and displayed in administrator log views without adequate security filtering.
The technical exploitation of this vulnerability occurs when an attacker registers or logs in using a malicious username containing embedded script code. When administrators subsequently view the login logs through the administrative interface, the improperly sanitized username gets rendered directly into the web page context, allowing the malicious script to execute within the administrator's browser session. This creates a persistent XSS vector that can be leveraged for session hijacking, credential theft, or further malicious activities within the compromised administrative environment. The vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws where input data is not properly sanitized before being rendered to users.
The operational impact of this vulnerability extends beyond simple script execution as it fundamentally compromises the integrity of the administrative interface. An attacker who successfully exploits this vulnerability can potentially gain elevated privileges, modify content, delete files, or establish persistent backdoors within the CMS environment. The attack requires minimal user interaction since administrators typically view login logs as part of routine monitoring activities, making this vector particularly dangerous. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1566.001 for spearphishing attachment, as it enables the delivery of malicious payloads through the administrative log viewing process.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. The primary fix involves sanitizing all user-provided input, particularly username fields, before storing or displaying them in administrative contexts. Implementing proper HTML entity encoding when rendering user data in administrative interfaces prevents script execution. Additionally, administrators should enforce strict access controls and monitor login activities more closely. The vulnerability demonstrates the importance of principle of least privilege and proper input sanitization as outlined in OWASP Top Ten security principles. Organizations should also consider implementing content security policies and regular security audits to detect similar issues in other components of their CMS infrastructure.