CVE-2016-20089: Iperius Remote Unquoted Service Path Vulnerability

CVE-2016-20089 describes an unquoted service path vulnerability impacting Iperius Remote version 1.7.0. This flaw allows a local attacker to escalate privileges to SYSTEM. The vulnerability arises when the Iperius Remote service is installed in a directory path containing spaces (e.g., C:\Program Files\Iperius Remote\), but the service executable path is not enclosed in quotation marks in the Windows registry. An attacker can exploit this by placing a specially named malicious executable (e.g., Program.exe) in an earlier part of the path (e.g., C:\). When the vulnerable service attempts to start, the operating system will incorrectly interpret the path and execute the attacker's malicious payload with SYSTEM privileges, granting full control over the compromised system. This vulnerability has a CVSS v3.1 Base Score of 7.8, indicating high severity.

Attack Chain

1. Vulnerability Identification: An attacker with local user privileges identifies an Iperius Remote 1.7.0 service installed on a Windows system with an unquoted service path, typically in a directory containing spaces (e.g., C:\Program Files\Iperius Remote\IperiusRemoteService.exe).
2. Payload Placement: The attacker places a malicious executable, for example, named Program.exe, into the root directory of the drive (e.g., C:\Program.exe).
3. Persistence Establishment: The malicious executable is designed to perform its intended actions, such as creating a backdoor or enabling remote access, to maintain control.
4. Triggering Execution: The attacker either waits for the next scheduled service restart or system reboot, or manually triggers a service restart (if permitted by current privileges).
5. Path Interpretation: When the Iperius Remote service attempts to start, the Windows Service Control Manager, due to the unquoted path, first attempts to execute C:\Program.exe instead of the legitimate C:\Program Files\Iperius Remote\IperiusRemoteService.exe.
6. Privilege Escalation: The attacker's C:\Program.exe is executed with the high privileges of the Iperius Remote service, which typically runs as the SYSTEM user.
7. Arbitrary Code Execution: The malicious Program.exe payload executes with SYSTEM privileges, granting the attacker full control over the system, enabling further actions like data exfiltration, deploying additional malware, or creating new privileged user accounts.

Impact

Successful exploitation of CVE-2016-20089 leads to local privilege escalation from a standard user account to SYSTEM privileges. This grants the attacker complete control over the compromised Windows system, bypassing security controls, installing rootkits, creating new administrative users, or disabling critical security software. While no specific victim count or targeted sectors are detailed, any organization utilizing Iperius Remote 1.7.0 on Windows systems is susceptible, facing severe consequences including data breach, system compromise, and further network infiltration.

Recommendation

• Patch CVE-2016-20089: Update Iperius Remote to a version higher than 1.7.0 that addresses the unquoted service path vulnerability immediately.
• Implement Quoted Paths: Ensure all Windows services are installed with their executable paths enclosed in quotation marks in the registry, especially for services located in directories containing spaces.
• Deploy Sigma Rule for Execution: Deploy the "Detect CVE-2016-20089 Exploitation - Unquoted Service Path Execution" Sigma rule to your SIEM to alert on suspicious process executions from common unquoted service path prefixes.
• Deploy Sigma Rule for File Creation: Deploy the "Detect Suspicious Executable Creation in Unquoted Service Path Locations" Sigma rule to your SIEM to identify attacker attempts to stage malicious executables.
• Enable Process Creation Logging: Ensure process_creation logging (e.g., via Sysmon) is enabled on all Windows endpoints to support the detection rules provided.
• Enable File Event Logging: Ensure file_event logging (e.g., via Sysmon) is enabled on all Windows endpoints to support detection of suspicious file creations.