CVE-2017-17464 in K7
Summary
by MITRE
K7Sentry.sys 15.1.0.59 in K7 Antivirus 15.1.0309 has a NULL pointer dereference via a 0x95002570 DeviceIoControl request.
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Analysis
by VulDB Data Team • 12/12/2019
The vulnerability identified as CVE-2017-17464 represents a critical NULL pointer dereference flaw within the K7Sentry.sys kernel driver component of K7 Antivirus version 15.1.0.59. This issue manifests through a specific DeviceIoControl request with the control code 0x95002570, which when processed by the vulnerable driver can lead to system instability and potential privilege escalation. The kernel driver K7Sentry.sys operates at the highest privilege level within the Windows operating system, making any flaw in its implementation particularly dangerous as it can be exploited to gain unauthorized system access or cause denial of service conditions.
The technical exploitation of this vulnerability occurs when malicious software or an attacker sends a crafted DeviceIoControl request to the K7Sentry.sys driver with the specific control code 0x95002570. This particular control code triggers a code path within the driver where a pointer variable is not properly validated before being dereferenced, leading to a NULL pointer dereference condition. This type of flaw falls under the Common Weakness Enumeration category CWE-476, which specifically addresses NULL pointer dereference vulnerabilities that can result in application crashes or system instability. The vulnerability exists because the driver fails to validate input parameters before processing them, creating an execution path where memory is accessed without proper bounds checking or null validation.
The operational impact of CVE-2017-17464 extends beyond simple system crashes, as it can potentially enable attackers to execute arbitrary code with kernel-level privileges. When the NULL pointer dereference occurs, the system typically experiences a blue screen of death or system hang, resulting in denial of service conditions that can be exploited by attackers to disrupt critical services. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1068, which involves exploiting local system privileges to gain elevated access. The attack surface is particularly concerning because kernel drivers are designed to run with the highest system privileges, meaning successful exploitation could allow attackers to bypass standard security controls, modify system memory, or install persistent backdoors.
Mitigation strategies for this vulnerability require immediate patching of the K7 Antivirus software to the latest version that contains the fix for this NULL pointer dereference issue. System administrators should also implement defensive measures such as disabling unnecessary kernel drivers, monitoring for suspicious DeviceIoControl calls, and applying the principle of least privilege to limit the potential impact of such vulnerabilities. Additionally, organizations should consider implementing endpoint detection and response solutions that can identify anomalous behavior patterns associated with driver exploitation attempts. The vulnerability demonstrates the importance of proper input validation in kernel-mode drivers and highlights the necessity for thorough security testing of antivirus and security software components that operate at the system level, as these components can become attack vectors if not properly secured against null pointer dereference conditions.