# Exploit Title: BlueStacks 2.5.55 Unquoted Service Path Privilege Escalation # Date: 24/09/2016 # Author: Yunus YILDIRIM (@Th3GundY) # Team: CT-Zer0 (@CRYPTTECH) # Website: http://yildirimyunus.com # Contact: yunusyildirim@protonmail.com # Category: local # Vendor Homepage: http://www.bluestacks.com/ # Version: Software Version <= 2.5.55 # Tested on: Windows 7-10 x86/x64 1. Description BlueStacks Log Rotator Service (BstHdLogRotatorSvc) installs as a service with an unquoted service path running with SYSTEM privileges. This could potentially allow an authorized but non-privileged local user to execute arbitrary code with elevated privileges on the system. 2. Proof of Concept C:\>sc qc BstHdLogRotatorSvc [SC] QueryServiceConfig SUCCESS SERVICE_NAME: BstHdLogRotatorSvc TYPE : 10 WIN32_OWN_PROCESS START_TYPE : 3 DEMAND_START ERROR_CONTROL : 1 NORMAL BINARY_PATH_NAME : C:\Program Files (x86)\Bluestacks\HD-LogRotatorService.exe LOAD_ORDER_GROUP : TAG : 0 DISPLAY_NAME : BlueStacks Log Rotator Service DEPENDENCIES : SERVICE_START_NAME : LocalSystem 3. Exploit: A successful attempt would require the local attacker must insert an executable file in the path of the service. Upon service restart or system reboot, the malicious code will be run with elevated privileges. Additional notes : Fixed in version v2.5.61 Vulnerability Disclosure Timeline: ========================= 24/09/2016 - Contact With Vendor 28/09/2016 - Vendor Response 04/10/2016 - Release Fixed Version