CVE-2007-0856 in PC-Cillin Internet Security
Summary
by MITRE
TmComm.sys 1.5.0.1052 in the Trend Micro Anti-Rootkit Common Module (RCM), with the VsapiNI.sys 3.320.0.1003 scan engine, as used in Trend Micro PC-cillin Internet Security 2007, Antivirus 2007, Anti-Spyware for SMB 3.2 SP1, Anti-Spyware for Consumer 3.5, Anti-Spyware for Enterprise 3.0 SP2, Client / Server / Messaging Security for SMB 3.5, Damage Cleanup Services 3.2, and possibly other products, assigns Everyone write permission for the \\.\TmComm DOS device interface, which allows local users to access privileged IOCTLs and execute arbitrary code or overwrite arbitrary memory in the kernel context.
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Analysis
by VulDB Data Team • 11/25/2024
The vulnerability described in CVE-2007-0856 represents a critical privilege escalation flaw within Trend Micro's anti-rootkit components that affects multiple security products from 2007. This issue stems from improper access control configuration in the TmComm.sys driver, which is part of the Trend Micro Anti-Rootkit Common Module (RCM) framework. The vulnerability specifically impacts the \.\TmComm DOS device interface where the driver incorrectly grants Everyone write permissions, creating a fundamental security flaw that undermines the integrity of the system's security architecture.
The technical implementation of this vulnerability involves the exploitation of a weak DACL (Discretionary Access Control List) configuration within the Windows kernel driver model. When the VsapiNI.sys scan engine interacts with TmComm.sys, the driver fails to properly restrict write access to the communication interface, allowing any local user account to write to the device. This misconfiguration enables attackers to send specially crafted IOCTL (Input/Output Control) requests that can manipulate kernel memory directly. The vulnerability falls under CWE-276, which specifically addresses incorrect permissions for critical resources, and represents a classic case of insufficient privilege checking in kernel-mode drivers.
The operational impact of this vulnerability is severe and far-reaching, as it allows local users to achieve kernel-level code execution without requiring administrative privileges. Attackers can leverage this flaw to execute arbitrary code in kernel context, potentially leading to complete system compromise. The ability to overwrite arbitrary memory in kernel space creates opportunities for privilege escalation, rootkit installation, and persistent system compromise. This vulnerability directly maps to ATT&CK technique T1068, which covers 'Local Privilege Escalation', and T1543, covering 'Create or Modify System Process'. The exploitation of this vulnerability effectively bypasses the security model of the operating system by allowing unprivileged users to gain elevated privileges through kernel manipulation.
Mitigation strategies for this vulnerability require immediate attention from system administrators and security teams. The most effective immediate solution involves patching the affected Trend Micro products to versions that properly restrict access permissions on the TmComm device interface. Organizations should also implement the principle of least privilege by restricting write access to kernel interfaces and monitoring for suspicious IOCTL activity on known vulnerable device names. Additionally, system hardening measures including disabling unnecessary kernel drivers and implementing kernel-mode code integrity checks can help reduce the attack surface. The vulnerability demonstrates the critical importance of proper access control implementation in kernel-mode components and the necessity of thorough security testing of anti-malware driver components that operate with elevated privileges.