Description
Joomla! Core is prone to multiple vulnerabilities, including cross-site scripting and security bypass vulnerabilities. Exploiting these issues could allow an attacker to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site, allowing the attacker to steal cookie-based authentication credentials, or to perform otherwise restricted actions and subsequently upload swf files. Joomla! Core versions 3.x.x ranging from 3.2.0 and up to and including 3.6.5 are vulnerable.
Remediation
Update to Joomla! Core version 3.7.0 or latest
References
https://developer.joomla.org/security-centre/684-core-xss-vulnerability.html
https://developer.joomla.org/security-centre/687-core-xss-vulnerability.html
https://developer.joomla.org/security-centre/689-core-acl-violations.html
Related Vulnerabilities
Joomla Unrestricted Upload of File with Dangerous Type Vulnerability (CVE-2018-11322)
WordPress Plugin Advanced Custom Fields (ACF) PHP Object Injection (5.7.10)
Jboss EAP Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (CVE-2014-3530)
Jenkins Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (CVE-2018-1000862)