The Privileges portion of the web GUI and the XMLRPC API in Apache VCL 2.3.x before 2.3.2, 2.2.x before 2.2.2 and 2.1 allow remote authenticated users with nodeAdmin, manageGroup, resourceGrant, or userGrant permissions to gain privileges, cause a denial of service, or conduct cross-site scripting (XSS) attacks by leveraging improper data validation.