CVE-2018-6776 in Jiangmin
Summary
by MITRE
In Jiangmin Antivirus 16.0.0.100, the driver file (KSysCall.sys) allows local users to cause a denial of service (BSOD) or possibly have unspecified other impact because of not validating input values from IOCtl 0x9A00813C.
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Analysis
by VulDB Data Team • 01/02/2020
The vulnerability identified as CVE-2018-6776 resides within the Jiangmin Antivirus software version 16.0.0.100, specifically within its kernel-mode driver component known as KSysCall.sys. This driver operates at the highest privilege level within the Windows operating system, making it a critical component that requires robust input validation to prevent exploitation. The flaw manifests through improper validation of input parameters received through the IOCTL (Input/Output Control) interface with the specific control code 0x9A00813C, which represents a mechanism for communication between user-mode applications and kernel-mode drivers.
The technical nature of this vulnerability stems from the driver's failure to validate input values received through the specified IOCTL command, creating a potential pathway for privilege escalation and system instability. When a local user submits malformed or unexpected input parameters to the KSysCall.sys driver through the vulnerable IOCTL interface, the driver processes these inputs without adequate sanitization or verification. This lack of input validation creates conditions where the driver may attempt to execute operations with invalid memory addresses or corrupted data structures, leading to system crashes or unpredictable behavior. The vulnerability specifically targets the kernel-mode execution context where the driver operates, making it particularly dangerous as it can potentially compromise the entire operating system's stability and security posture.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as the potential for unspecified other impacts suggests additional security risks that could be exploited by malicious actors. A local attacker with access to the system could trigger a blue screen of death (BSOD) by sending crafted input to the vulnerable driver, effectively causing a system crash and denial of service for legitimate users. However, the unspecified nature of additional potential impacts indicates that this vulnerability might also provide opportunities for privilege escalation or information disclosure, as the driver's failure to validate input could potentially allow execution of arbitrary code within kernel space. This represents a significant security concern since kernel-mode code operates with the highest privileges and can directly manipulate system resources, potentially enabling attackers to bypass security controls or establish persistent access.
The vulnerability aligns with CWE-129, Input Validation, which addresses improper validation of input values that can lead to various security issues including buffer overflows and privilege escalation. This weakness in the driver's design creates an attack surface that can be exploited through the Windows driver model's interface mechanisms. From an ATT&CK framework perspective, this vulnerability could be leveraged as part of the privilege escalation tactic, specifically under the T1068 technique for 'Exploitation for Privilege Escalation' where local users can exploit kernel vulnerabilities to gain elevated privileges. The attack vector involves local user execution, making it a low-barrier entry point for attackers who already have system access, and the exploitation requires no special network connectivity or external dependencies.
Mitigation strategies for this vulnerability should focus on immediate patching of the Jiangmin Antivirus software to the latest version that addresses the input validation issues within the KSysCall.sys driver. System administrators should implement monitoring for suspicious driver activity and ensure that only legitimate, signed drivers are allowed to execute on the system through driver signature enforcement mechanisms. The principle of least privilege should be enforced by restricting local user access to potentially dangerous system interfaces, and regular security assessments should be conducted to identify similar input validation weaknesses in other kernel-mode components. Additionally, implementing behavioral monitoring for abnormal system crashes or driver behavior can help detect exploitation attempts before they result in successful compromise, as the BSOD condition represents a clear indicator of attempted exploitation.