Vulnerabilities > CVE-2020-8283 - Improper Privilege Management vulnerability in Citrix Virtual Apps and Desktops, Xenapp and Xendesktop

047910
CVSS 9.0 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
low complexity
citrix
CWE-269
critical

Summary

An authorised user on a Windows host running Citrix Universal Print Server can perform arbitrary command execution as SYSTEM in CVAD versions before 2009, 1912 LTSR CU1 hotfixes CTX285870 and CTX286120, 7.15 LTSR CU6 hotfix CTX285344 and 7.6 LTSR CU9.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.