CVE-2017-9247 in Windows Mobile Broadband Driver Package
Summary
by MITRE
Multiple unquoted Windows search path vulnerabilities in Sierra Wireless Windows Mobile Broadband Driver Packages (MBDP) allow local users to gain privileges via a Trojan horse executable file.
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Analysis
by VulDB Data Team • 11/03/2019
The vulnerability identified as CVE-2017-9247 represents a critical security flaw within the Sierra Wireless Windows Mobile Broadband Driver Packages that affects Windows operating systems. This issue stems from improper handling of search paths during driver installation processes, creating exploitable conditions that can be leveraged by local attackers to elevate their privileges. The vulnerability specifically targets the way Windows resolves executable paths when installing broadband driver packages, creating opportunities for malicious actors to place crafted executables in strategic locations that will be executed with elevated privileges.
The technical root cause of this vulnerability lies in the improper implementation of unquoted search path handling within the driver installation framework. When Windows processes driver installation commands, it follows a specific search order to locate required executables and libraries. In the affected Sierra Wireless MBDP versions, the system fails to properly quote path names containing spaces, allowing attackers to manipulate the search path resolution. This behavior aligns with CWE-428, which describes the vulnerability of unquoted search paths in Windows systems where spaces in directory names create opportunities for path injection attacks. The flaw essentially allows an attacker to place a malicious executable in a location that will be executed before the legitimate system component, bypassing normal security checks and access controls.
The operational impact of this vulnerability is significant as it enables local privilege escalation attacks that can be executed by any user with access to the affected system. An attacker who gains access to a low-privilege account can exploit this vulnerability to execute malicious code with system-level privileges, potentially leading to complete system compromise. The attack vector requires the attacker to have local access to the target system, but this is often achievable through various initial compromise techniques such as phishing, credential theft, or exploitation of other vulnerabilities. Once successful, the attacker can execute arbitrary code with elevated privileges, potentially gaining access to sensitive system resources, modifying critical system files, or establishing persistent access to the compromised system.
This vulnerability demonstrates characteristics consistent with the attack techniques described in the MITRE ATT&CK framework under the Privilege Escalation tactic, specifically targeting the "Exploitation for Privilege Escalation" technique. The attack leverages the inherent Windows search path behavior to execute malicious code with elevated privileges, making it particularly dangerous as it can be exploited without requiring specialized tools or advanced knowledge of system internals. The vulnerability affects multiple versions of Windows operating systems including Windows 7, Windows 8, Windows 8.1, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, and Windows Server 2016, indicating the widespread nature of the issue. Security researchers have noted that this vulnerability is particularly concerning because it can be exploited through legitimate system installation processes, making it difficult to detect and prevent through traditional security monitoring approaches.
Mitigation strategies for CVE-2017-9247 should include immediate installation of vendor patches provided by Sierra Wireless and Microsoft, as well as implementing proper access controls and system hardening measures. Organizations should ensure that all systems are updated with the latest security patches and that the principle of least privilege is enforced to limit the potential impact of successful exploitation attempts. System administrators should also conduct thorough security assessments to identify and remediate any instances of unquoted search path vulnerabilities in other software components. The recommended approach involves applying the vendor-specific patches that address the root cause of the search path handling issue and implementing monitoring procedures to detect anomalous executable behavior that might indicate exploitation attempts. Additionally, security awareness training for system administrators can help prevent the installation of untrusted software that might exploit similar vulnerabilities in other components of the system infrastructure.