CVE-2007-0709 in Firewall Pro
Summary
by MITRE
cmdmon.sys in Comodo Firewall Pro (formerly Comodo Personal Firewall) 2.4.16.174 and earlier does not validate arguments that originate in user mode for the (1) NtCreateSection, (2) NtOpenProcess, (3) NtOpenSection, (4) NtOpenThread, and (5) NtSetValueKey hooked SSDT functions, which allows local users to cause a denial of service (system crash) and possibly gain privileges via invalid arguments.
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Analysis
by VulDB Data Team • 10/13/2017
The vulnerability identified as CVE-2007-0709 resides within the cmdmon.sys kernel driver component of Comodo Firewall Pro version 2.4.16.174 and earlier. This driver operates as a critical system module responsible for monitoring and controlling various Windows kernel operations through System Service Descriptor Table (SSDT) hooking mechanisms. The flaw manifests in the driver's insufficient validation of user-mode arguments passed to five specific Windows NT native API functions including NtCreateSection, NtOpenProcess, NtOpenSection, NtOpenThread, and NtSetValueKey. These functions represent fundamental kernel operations that control memory mapping, process access, and registry manipulation within the Windows operating system.
The technical nature of this vulnerability stems from the driver's failure to implement proper argument validation within its hooked SSDT functions, creating a path for malicious input to traverse from user mode into kernel space without adequate sanitization. When local users submit invalid or malformed arguments to these functions through the hooked driver interface, the kernel driver processes these inputs without proper bounds checking or parameter validation. This absence of input validation creates a condition where malformed parameters can cause the kernel to execute invalid memory operations or corrupt critical system data structures, ultimately leading to system instability and potential privilege escalation.
The operational impact of this vulnerability presents a dual threat to system security and stability. Local attackers can exploit this weakness to trigger system crashes and denial of service conditions, effectively rendering the protected system unavailable to legitimate users. More critically, the vulnerability may enable privilege escalation attacks where malicious actors could potentially elevate their privileges from standard user level to kernel level access. This escalation capability arises from the fact that the driver operates with elevated privileges in kernel space, and improper input handling could allow attackers to manipulate kernel data structures or execute arbitrary code with system-level privileges. The vulnerability's exploitation requires local system access but does not necessitate network connectivity, making it particularly dangerous in environments where local access is possible.
Security professionals should recognize this vulnerability as a classic example of insufficient input validation in kernel-mode drivers, which aligns with CWE-20 (Improper Input Validation) and CWE-787 (Out-of-bounds Write) categories. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under T1068 (Local Port Forwarding) and T1059 (Command and Scripting Interpreter) where local privilege escalation is achieved through kernel-level manipulation. Organizations should implement immediate mitigations including updating to Comodo Firewall Pro versions that address this vulnerability, disabling the problematic driver if not essential, and monitoring for suspicious system crashes or privilege escalation attempts. Additionally, system administrators should conduct comprehensive security audits to identify any other kernel-mode drivers that may exhibit similar validation deficiencies, as this represents a broader class of vulnerabilities affecting system security integrity.