CVE-2018-15880 in Joomla
Summary
by MITRE
An issue was discovered in Joomla! before 3.8.12. Inadequate output filtering on the user profile page could lead to a stored XSS attack.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/06/2023
The vulnerability identified as CVE-2018-15880 represents a critical stored cross-site scripting flaw within the Joomla! content management system affecting versions prior to 3.8.12. This security weakness resides in the user profile page functionality where insufficient output filtering mechanisms fail to properly sanitize user-supplied data before rendering it within web pages. The flaw allows authenticated attackers with user profile editing privileges to inject malicious scripts that persist in the application's database and execute whenever the profile page is accessed by other users.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding practices within Joomla!'s user profile handling components. When users submit profile information containing malicious script code, the application fails to adequately escape or filter special characters that could be interpreted as executable code by web browsers. This insufficient sanitization creates a persistent XSS vector where the malicious payload stored in the database executes in the context of other users' browsers who view the compromised profile page. The vulnerability specifically impacts the rendering of user-generated content without proper context-aware escaping mechanisms that would neutralize potentially dangerous input.
From an operational perspective, this stored XSS vulnerability poses significant risks to Joomla! installations as it enables attackers to execute arbitrary JavaScript code within the browser context of authenticated users. The attack requires minimal privileges since only users with profile editing capabilities need to be compromised, making it particularly dangerous in environments where user accounts have elevated permissions. Successful exploitation could lead to session hijacking, credential theft, privilege escalation, or redirection to malicious sites. The persistent nature of stored XSS means that once the malicious script is injected, it continues to affect users until the database entry is manually removed or the application is patched.
Security practitioners should note this vulnerability aligns with CWE-79 which describes improper neutralization of input during web output rendering, and maps to ATT&CK technique T1059.007 for scripting languages and T1566 for credential access through social engineering. The recommended mitigation strategy involves immediately upgrading to Joomla! version 3.8.12 or later where proper output filtering has been implemented. Additionally, administrators should implement web application firewalls, deploy content security policies, and conduct regular security audits of user profile pages. Organizations should also consider implementing strict input validation for all user-supplied content and regularly training users on recognizing potential XSS attack vectors while maintaining comprehensive monitoring of profile modification activities.