CVE-2018-9991 in Frog
Summary
by MITRE
Frog CMS 0.9.5 has XSS via the /admin/?/user/add Name or Username parameter.
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Analysis
by VulDB Data Team • 01/24/2020
The vulnerability identified as CVE-2018-9991 represents a cross-site scripting flaw in Frog CMS version 0.9.5 that specifically targets the administrative user management functionality. This issue resides within the parameter handling mechanism of the user addition interface, where the application fails to properly sanitize user-supplied input before rendering it in the web response. The vulnerability affects the Name and Username fields during the user creation process, making it exploitable by malicious actors who can inject malicious scripts into these parameters.
This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is classified as a critical security weakness in web applications. The flaw demonstrates a classic input validation failure where the application does not implement proper output encoding or sanitization for user-controllable data. When administrators or other users interact with the vulnerable interface, the malicious script code gets executed in the context of their browser sessions, potentially leading to session hijacking, privilege escalation, or data exfiltration.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with a potential entry point for more sophisticated attacks within the administrative interface. An attacker could craft malicious payloads that, when processed by the vulnerable CMS, could redirect authenticated users to phishing sites, steal session cookies, or even modify user permissions. The vulnerability's exploitation requires minimal privileges as it targets the administrative user management interface, which is typically accessible to users with appropriate administrative rights.
The attack vector for CVE-2018-9991 follows the typical pattern described in the MITRE ATT&CK framework under the T1059 technique for command and scripting interpreter. The vulnerability allows for persistent script injection that can be triggered whenever the affected parameters are displayed in the administrative interface. This creates a persistent threat that can affect multiple users who view the malicious content, making it particularly dangerous in multi-user environments where administrators regularly review user lists.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. The recommended approach involves sanitizing all user inputs through proper HTML escaping before rendering them in web pages, implementing Content Security Policy headers to limit script execution, and conducting regular security code reviews to identify similar input handling flaws. Organizations should also consider implementing Web Application Firewall rules to detect and block known malicious payloads targeting this specific vulnerability. The most effective long-term solution requires updating to a patched version of Frog CMS or implementing proper input sanitization at the application level to prevent any future similar vulnerabilities from being exploited.