CVE-2015-8773 in File Lock Driver
Summary
by MITRE
Stack-based buffer overflow in McPvDrv.sys 4.6.111.0 in McAfee File Lock 5.x in McAfee Total Protection allows attackers to cause a denial of service (system crash) via a long vault GUID in an ioctl call.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/29/2018
The vulnerability identified as CVE-2015-8773 represents a critical stack-based buffer overflow flaw within the McPvDrv.sys kernel driver component of McAfee File Lock 5.x suite. This issue specifically affects McAfee Total Protection software versions utilizing the vulnerable driver module with version 4.6.111.0. The vulnerability manifests through improper input validation within the driver's ioctl handling mechanism, creating a condition where maliciously crafted input data can overflow the allocated stack buffer and overwrite adjacent memory locations. The flaw exists in the kernel-mode driver component that manages file locking functionality, making it particularly dangerous as it operates with elevated privileges and can directly interact with system memory structures.
The technical exploitation of this vulnerability occurs when an attacker submits a specially crafted long vault GUID through an ioctl (input/output control) system call to the vulnerable McPvDrv.sys driver. The driver fails to properly validate the length of the GUID parameter before copying it into a fixed-size stack buffer, resulting in a buffer overflow condition. This overflow can corrupt the stack frame, potentially leading to arbitrary code execution or system crash. The vulnerability is classified under CWE-121 Stack-based Buffer Overflow, which is a well-documented weakness in software development where data written to a stack buffer exceeds the buffer's allocated size. The attack vector requires local system access or privilege escalation to execute successfully, as the vulnerable driver typically operates with kernel-level privileges.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as the system crash can result in complete system instability and potential data loss. When the buffer overflow occurs, it can corrupt critical kernel memory structures, leading to unpredictable behavior including system hangs, blue screen errors, or complete system reboot. This makes the vulnerability particularly concerning for enterprise environments where McAfee Total Protection is deployed, as it can disrupt business operations and potentially provide an attack surface for more sophisticated exploitation attempts. The vulnerability affects the stability and reliability of the entire McAfee security suite, as the compromised driver component directly handles file access control and protection mechanisms.
Mitigation strategies for CVE-2015-8773 should prioritize immediate patching of the affected McAfee Total Protection software to the latest available version that addresses this specific buffer overflow vulnerability. Organizations should implement network segmentation and access controls to limit potential exploitation opportunities, as the vulnerability requires local system access or privilege escalation to be effectively exploited. System administrators should monitor for unusual system crashes or stability issues that might indicate exploitation attempts, and maintain comprehensive backup and recovery procedures to ensure business continuity. The vulnerability aligns with ATT&CK technique T1059.003 for command and scripting interpreter usage, as exploitation may involve command execution through the compromised driver interface. Additionally, the vulnerability demonstrates characteristics of T1543.003 for create or modify system process, as the compromised driver can directly affect system process behavior and memory management. Organizations should also consider implementing kernel-mode driver integrity checking mechanisms and regular security assessments to identify similar vulnerabilities in other security software components.