CVE-2017-9769 in Synapse
Summary
by MITRE
A specially crafted IOCTL can be issued to the rzpnk.sys driver in Razer Synapse 2.20.15.1104 that is forwarded to ZwOpenProcess allowing a handle to be opened to an arbitrary process.
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Analysis
by VulDB Data Team • 11/03/2019
The vulnerability identified as CVE-2017-9769 represents a critical privilege escalation flaw within the Razer Synapse 2.20.15.1104 software ecosystem, specifically targeting the rzpnk.sys kernel driver. This issue stems from improper input validation within the driver's implementation of the DeviceIoControl function, which processes IOCTL (Input/Output Control) requests from user-mode applications. The rzpnk.sys driver operates at kernel level with elevated privileges, making it a prime target for attackers seeking to escalate their privileges from standard user to system-level access. The vulnerability manifests when a maliciously crafted IOCTL request is sent to the driver, which then forwards this request to the Windows kernel function ZwOpenProcess without adequate validation of the parameters.
The technical exploitation of this vulnerability relies on the driver's failure to properly validate the ProcessId parameter within the IOCTL request structure. When ZwOpenProcess is called with a malformed or crafted ProcessId, it can open handles to processes that the calling user normally wouldn't have access to, including system processes or other user processes. This creates a direct pathway for privilege escalation attacks, allowing attackers to gain unauthorized access to sensitive system resources and potentially execute arbitrary code with system-level privileges. The flaw exists in the driver's IOCTL handling mechanism, where the ProcessId parameter is directly passed through to the kernel without proper validation or access control checks.
The operational impact of CVE-2017-9769 extends beyond simple privilege escalation, as it fundamentally undermines the security model of the Windows operating system. Attackers can leverage this vulnerability to target any process running on the system, potentially accessing sensitive data, modifying system processes, or establishing persistent backdoors. The vulnerability affects all users running Razer Synapse 2.20.15.1104, making it particularly dangerous as it requires no special privileges to exploit. This flaw aligns with CWE-121, which describes the weakness of stack-based buffer overflows, though this specific case involves improper parameter validation rather than buffer manipulation. The vulnerability also maps to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation,' and T1059, which covers 'Command and Scripting Interpreter,' as attackers can use the escalated privileges to execute malicious commands.
Mitigation strategies for CVE-2017-9769 must address both immediate remediation and long-term security posture improvements. The most effective immediate solution involves updating to a patched version of Razer Synapse, as the vulnerability was resolved in subsequent releases. Organizations should implement strict software update policies to ensure all systems receive security patches promptly. Additionally, users should disable or uninstall the affected Razer Synapse components if they cannot immediately update, as running the vulnerable driver creates an attack surface that can be exploited by malware or malicious actors. System administrators should also consider implementing application whitelisting policies that restrict execution of unsigned kernel-mode drivers, and monitor for suspicious IOCTL activity that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper kernel driver security implementation and highlights the risks associated with third-party drivers that operate with elevated privileges without adequate input validation and access controls.