CVE-2021-22928: 
Citrix Virtual Delivery Agent (VDA) vulnerability analysis and mitigation

A vulnerability (CVE-2021-22928) was identified in Citrix Virtual Apps and Desktops that affects Windows VDA systems with either Citrix Profile Management or Citrix Profile Management WMI Plugin installed. The vulnerability was discovered in January 2021 and publicly disclosed in August 2021. The affected systems include Citrix Virtual Apps and Desktops versions from 2006 to 2106, XenApp 7.15, and XenDesktop 7.15 (NVD).

The vulnerability is classified as a local privilege escalation issue with a CVSS v3.1 Base Score of 7.8 (HIGH) and a vector string of CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. The CVSS v2.0 Base Score is 7.2 (HIGH) with a vector string of (AV:L/AC:L/Au:N/C:C/I:C/A:C). The vulnerability is related to improper access control (CWE-284) that could allow privilege escalation (NVD).

If successfully exploited, this vulnerability allows a local user to escalate their privilege level to SYSTEM on the affected Windows VDA system, potentially giving them complete control over the system (CVE).

The vulnerability requires local access to the system and low privilege level for exploitation. No user interaction is needed once the attacker has the required access (NVD).

Citrix has released security updates to address this vulnerability. Users should apply the appropriate patches based on their deployed version of Citrix Virtual Apps and Desktops (Citrix Advisory).