CVE-2017-17429 in K7
Summary
by MITRE
In K7 Antivirus Premium before 15.1.0.53, user-controlled input to the K7Sentry device is not sufficiently authenticated: a local user with a LOW integrity process can access a raw hard disk by sending a specific IOCTL.
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Analysis
by VulDB Data Team • 12/23/2019
CVE-2017-17429 represents a critical privilege escalation vulnerability within K7 Antivirus Premium versions prior to 15.1.0.53, specifically affecting the K7Sentry device driver component. This vulnerability stems from insufficient input validation and authentication mechanisms within the kernel-level driver that handles device control operations. The flaw allows a local attacker operating within a LOW integrity process to exploit a specific IOCTL (Input/Output Control) command that provides direct access to raw hard disk devices, bypassing normal security boundaries that should prevent such unauthorized access.
The technical implementation of this vulnerability involves the K7Sentry driver's failure to properly validate user-supplied input parameters when processing IOCTL requests. When a malicious user sends a crafted IOCTL command to the device, the driver does not adequately authenticate or sanitize the input, creating an attack surface where unprivileged processes can manipulate the driver to perform operations typically restricted to kernel-level processes. This represents a classic case of insufficient input validation, which maps to CWE-20, "Improper Input Validation," and more specifically CWE-787, "Out-of-bounds Write," when considering the potential for memory corruption through malformed IOCTL parameters.
From an operational perspective, this vulnerability creates a significant risk for system compromise as it allows attackers to bypass standard security controls that normally protect against unauthorized disk access. A local user with LOW integrity privileges can leverage this flaw to access raw disk devices, potentially enabling data exfiltration, system file manipulation, or the installation of persistent backdoors. The attack requires minimal privileges and can be executed without requiring administrative rights, making it particularly dangerous in multi-user environments where users might have limited system access but still need to interact with antivirus software components.
The vulnerability's impact aligns with ATT&CK technique T1068, "Exploitation for Privilege Escalation," and T1059, "Command and Scripting Interpreter," as attackers can use the raw disk access to execute malicious code or modify system files. The lack of proper authentication in the IOCTL handling mechanism also violates fundamental security principles of least privilege and principle of least privilege enforcement, where the driver should only permit operations from authenticated and authorized processes. Organizations running vulnerable versions of K7 Antivirus Premium face significant risk of unauthorized system access, data theft, and potential complete system compromise, particularly in environments where multiple users share systems or where the antivirus software is configured with overly permissive access controls.
The recommended mitigation strategy involves immediate patching to version 15.1.0.53 or later, which addresses the insufficient authentication issue in the K7Sentry driver. Additionally, system administrators should implement proper access controls and monitor for unauthorized IOCTL activity from low-integrity processes. Network segmentation and privilege separation should be enforced to limit the potential impact of such vulnerabilities. The vulnerability also highlights the importance of driver security testing and proper input validation in kernel-mode components, as these areas represent critical attack surfaces where insufficient security controls can lead to severe privilege escalation opportunities.