Microsoft Windows Group Policy Client Service Link Resolution Privilege Escalation Vulnerability
Vulnerability Details
This vulnerability allows local attackers to escalate privileges on affected installations of Microsoft Windows. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the Group Policy Client service. By creating a junction, an attacker can abuse the service to gain control of files and folders. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of an administrator.
Additional Details
Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2020-16939
Disclosure Timeline
- 2020-08-05 - Vulnerability reported to vendor
- 2020-10-19 - Coordinated public release of advisory
Credit
Nabeel Ahmed (@rogue_kdc) of NTT
