CVE-2018-9151 in Internet Security
Summary
by MITRE
A NULL pointer dereference bug in the function ObReferenceObjectByHandle in the Kingsoft Internet Security 9+ kernel driver KWatch3.sys allows local non-privileged users to crash the system via IOCTL 0x80030030.
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Analysis
by VulDB Data Team • 01/18/2020
The vulnerability identified as CVE-2018-9151 represents a critical null pointer dereference flaw within the kernel-mode component of Kingsoft Internet Security 9+ software. This issue specifically affects the KWatch3.sys kernel driver responsible for system security monitoring functions. The vulnerability manifests when the ObReferenceObjectByHandle function processes IOCTL 0x80030030 requests, creating a scenario where untrusted input can lead to system instability. The flaw resides in the driver's insufficient validation of input parameters, allowing malicious local users to exploit this weakness without requiring administrative privileges. This particular vulnerability demonstrates a classic kernel-level programming error where the system attempts to dereference a null pointer during object reference operations, resulting in immediate system termination.
The technical implementation of this vulnerability stems from improper input validation within the kernel driver's IOCTL handling mechanism. When a local user submits a specially crafted IOCTL 0x80030030 request to the KWatch3.sys driver, the ObReferenceObjectByHandle function fails to properly validate the object handle parameter before attempting to reference it. This validation failure creates a path where a null pointer can be passed to the dereferencing operation, causing an immediate system crash. The vulnerability aligns with CWE-476 which specifically addresses NULL pointer dereference conditions in software implementations. The attack vector requires local system access and does not necessitate elevated privileges, making it particularly concerning for security-conscious environments where users may have varying levels of system access.
From an operational perspective, this vulnerability presents a significant risk to system availability and stability within affected environments. Local non-privileged users can reliably crash the target system by simply executing the malicious IOCTL request, potentially leading to denial of service conditions that could disrupt legitimate user activities. The impact extends beyond simple system crashes as such vulnerabilities often indicate broader code quality issues within the kernel driver that may conceal additional security flaws. The vulnerability's exploitation does not require specialized tools or extensive knowledge, making it accessible to a wide range of threat actors including those with limited technical expertise. This characteristic significantly increases the potential attack surface and makes the vulnerability particularly dangerous in enterprise environments where user access controls may not be strictly enforced.
The recommended mitigation strategies for CVE-2018-9151 include immediate deployment of vendor-provided patches or updates to address the null pointer dereference condition in the KWatch3.sys driver. System administrators should prioritize updating the Kingsoft Internet Security 9+ software to versions that contain fixed implementations of the ObReferenceObjectByHandle function. Additionally, implementing monitoring solutions to detect unusual IOCTL activity patterns can help identify potential exploitation attempts. Network segmentation and user access controls should be reviewed to minimize the potential impact of local exploitation, as the vulnerability requires local system access but does not require administrative privileges. The vulnerability's classification under ATT&CK technique T1068 suggests that it could be leveraged as part of broader attack chains where initial compromise leads to privilege escalation or lateral movement. Organizations should also consider implementing kernel-mode protection mechanisms and runtime application control to prevent exploitation of similar vulnerabilities in other kernel drivers.