CVE-2017-17465 in K7
Summary
by MITRE
K7Sentry.sys 15.1.0.59 in K7 Antivirus 15.1.0309 has a NULL pointer dereference via a 0x95002574 DeviceIoControl request.
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Analysis
by VulDB Data Team • 12/12/2019
The vulnerability identified as CVE-2017-17465 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 specifically when processing DeviceIoControl requests with the ioctl code 0x95002574, which indicates a potential privilege escalation vector within the antivirus kernel module. The vulnerability exists within the device driver's handling of user-mode input, where insufficient validation allows malicious input to trigger a dereference of a null pointer, leading to system instability and potential exploitation.
The technical nature of this flaw falls under CWE-476 which specifically addresses NULL pointer dereference conditions in software implementations. This vulnerability operates at the kernel level within the Windows driver model, where the K7Sentry.sys driver fails to properly validate input parameters before attempting to dereference memory pointers. When an attacker sends a crafted DeviceIoControl request with the specific ioctl code 0x95002574, the driver's processing logic does not adequately check whether certain pointer variables have been initialized, resulting in a NULL pointer dereference that can cause the system to crash or potentially allow arbitrary code execution.
From an operational perspective, this vulnerability presents significant risk to systems running affected K7 Antivirus versions, as it can be exploited by local attackers or potentially remote attackers who can interact with the vulnerable driver interface. The impact extends beyond simple system crashes, as the null pointer dereference can lead to privilege escalation opportunities and system compromise. Attackers could leverage this vulnerability to gain elevated privileges within the system context, potentially allowing them to execute malicious code with kernel-level privileges, which represents a severe security risk. The vulnerability's exploitation requires minimal privileges to interact with the device driver, making it particularly dangerous in environments where users might have access to the antivirus interface.
The mitigation strategies for this vulnerability involve immediate patching of the K7 Antivirus software to the latest version that addresses this specific NULL pointer dereference issue. System administrators should also implement monitoring for unusual DeviceIoControl activity related to the K7Sentry.sys driver and consider disabling unnecessary driver interfaces until patches are applied. Additionally, implementing proper input validation and bounds checking within kernel drivers aligns with the defensive measures recommended by the ATT&CK framework under the technique of privilege escalation through kernel exploits. Organizations should also consider employing kernel-mode exploit detection mechanisms and maintaining updated security baselines that include proper driver signature validation to prevent exploitation of similar vulnerabilities in the future.