CVE-2019-25568: Memu Play Privilege Escalation Flaw

CVE-2019-25568 Overview

CVE-2019-25568 is a critical insecure file permissions vulnerability affecting Memu Play 6.0.7, an Android emulator for Windows. The vulnerability allows low-privilege users to escalate privileges to SYSTEM level by exploiting weak file permissions on the MemuService.exe executable in the installation directory. An attacker can rename the legitimate service executable and replace it with a malicious payload, which then executes with elevated privileges when the service restarts following a system reboot.

Critical Impact

Low-privilege local attackers can achieve complete system compromise by replacing a service executable that runs with SYSTEM privileges, enabling full control over the affected Windows host.

Affected Products

• Memu Play 6.0.7
• Earlier versions of Memu Play may also be affected

Discovery Timeline

• 2026-03-21 - CVE CVE-2019-25568 published to NVD
• 2026-03-23 - Last updated in NVD database

Technical Details for CVE-2019-25568

Vulnerability Analysis

This vulnerability stems from improper access control (CWE-306) on the Memu Play installation directory and its executable files. The MemuService.exe Windows service runs with SYSTEM-level privileges, making it a high-value target for privilege escalation attacks. Due to misconfigured file system permissions, low-privilege users have write access to the installation directory, allowing them to manipulate service executables.

The attack requires local access to the target system with any valid user account. Once an attacker identifies the vulnerable permissions, they can rename the original MemuService.exe to a backup filename and place a malicious executable in its place. When the system reboots and the Memu service starts, Windows executes the attacker-controlled binary with SYSTEM privileges, resulting in complete system compromise.

Root Cause

The root cause of this vulnerability is the failure to implement proper file system access controls during Memu Play installation. The installer does not restrict write permissions on the installation directory to administrators only, violating the principle of least privilege. This configuration oversight allows any authenticated user to modify critical service executables that run with elevated privileges.

Attack Vector

The attack follows a straightforward privilege escalation pattern:

1. An attacker with low-privilege local access identifies the Memu Play installation directory (typically C:\Program Files\Microvirt\MEmu)
2. The attacker verifies write permissions exist on MemuService.exe
3. The legitimate service executable is renamed (e.g., to MemuService.exe.bak)
4. A malicious executable is placed at the original path with the name MemuService.exe
5. Upon system reboot, the MemuService starts automatically, executing the attacker's payload with SYSTEM privileges

The attack does not require any user interaction beyond the initial system access, and the malicious service will persist across reboots until detected and remediated. Technical details and a proof-of-concept are available at the Exploit-DB #46437 advisory.

Detection Methods for CVE-2019-25568

Indicators of Compromise

• Unexpected modifications to MemuService.exe file hash, size, or digital signature
• Presence of backup files such as MemuService.exe.bak or similar in the Memu installation directory
• Unusual process behavior or network connections originating from the MemuService process
• Windows Event Log entries indicating service executable changes or service failures

Detection Strategies

• Implement file integrity monitoring (FIM) on the Memu Play installation directory, particularly for MemuService.exe
• Monitor for permission changes on service executable directories using Windows Security Event ID 4670
• Deploy endpoint detection rules to alert on service executables with mismatched digital signatures
• Use SentinelOne's behavioral AI to detect anomalous process activity from known-good service paths

Monitoring Recommendations

• Configure alerts for any file modifications within C:\Program Files\Microvirt\MEmu\ directory
• Monitor Windows Service Control Manager events (Event IDs 7000, 7009, 7045) for service installation or failure patterns
• Implement periodic audits of file permissions on service executable directories
• Enable SentinelOne Deep Visibility for comprehensive endpoint telemetry and retrospective threat hunting

How to Mitigate CVE-2019-25568

Immediate Actions Required

• Review and remediate file permissions on the Memu Play installation directory to restrict write access to administrators only
• Verify the integrity of MemuService.exe by checking its digital signature and comparing file hashes against known-good values
• Consider uninstalling Memu Play 6.0.7 until a patched version is available from the vendor
• Implement application control policies to prevent unauthorized executable replacements

Patch Information

Users should upgrade to the latest version of Memu Play from the official MemuPlay website. Review the VulnCheck Advisory on MemuPlay for additional remediation guidance. If updating is not immediately possible, apply the file permission hardening workarounds below.

Workarounds

• Manually configure NTFS permissions on the Memu installation directory to grant write access only to Administrators and SYSTEM
• Use Windows Group Policy to enforce restrictive permissions on software installation directories
• Implement application whitelisting to prevent unauthorized executables from running as services
• Consider running Memu Play in a sandboxed or virtualized environment to limit privilege escalation impact

# PowerShell: Fix permissions on Memu installation directory
$path = "C:\Program Files\Microvirt\MEmu"
$acl = Get-Acl $path
$acl.SetAccessRuleProtection($true, $false)
$adminRule = New-Object System.Security.AccessControl.FileSystemAccessRule("BUILTIN\Administrators","FullControl","ContainerInherit,ObjectInherit","None","Allow")
$systemRule = New-Object System.Security.AccessControl.FileSystemAccessRule("NT AUTHORITY\SYSTEM","FullControl","ContainerInherit,ObjectInherit","None","Allow")
$usersRule = New-Object System.Security.AccessControl.FileSystemAccessRule("BUILTIN\Users","ReadAndExecute","ContainerInherit,ObjectInherit","None","Allow")
$acl.SetAccessRule($adminRule)
$acl.SetAccessRule($systemRule)
$acl.SetAccessRule($usersRule)
Set-Acl $path $acl