CVE-2011-0652 in Look 'n' Stop Firewall
Summary
by MITRE
lnsfw1.sys 6.0.2900.5512 in Look n Stop Firewall 2.06p4 and 2.07 allows local users to cause a denial of service (crash) via a crafted 0x80000064 IOCTL request that triggers an assertion failure. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 03/04/2025
The vulnerability described in CVE-2011-0652 represents a critical denial of service flaw within the Look n Stop Firewall 2.06p4 and 2.07 software suite. This issue specifically affects the lnsfw1.sys kernel driver component with version 6.0.2900.5512, which serves as the core firewall protection mechanism for the Look n Stop security solution. The vulnerability manifests when the system receives a specially crafted IOCTL (Input/Output Control) request with the operation code 0x80000064, which is typically used for communication between user-mode applications and kernel-mode drivers in Windows operating systems. This particular IOCTL command triggers an assertion failure within the driver's memory management routines, causing the system to crash and resulting in a complete denial of service condition.
The technical nature of this vulnerability stems from inadequate input validation within the kernel driver's IOCTL handling mechanism. When a local user executes a maliciously crafted IOCTL request, the driver fails to properly validate the parameters associated with the 0x80000064 operation, leading to an assertion failure that terminates the driver's execution. This type of vulnerability falls under the Common Weakness Enumeration category CWE-665 Improper Initialization, as the driver fails to properly initialize or validate critical data structures before processing user-supplied input. The assertion failure occurs at the kernel level, which means that the operating system's kernel becomes unstable and must be restarted to restore normal functionality. The impact is particularly severe because this vulnerability can be exploited by any local user account, including unprivileged users, making it a significant security risk for systems where local access is possible.
From an operational standpoint, this vulnerability creates substantial risks for organizations relying on Look n Stop Firewall for network protection. The denial of service condition can occur at any time when the malicious IOCTL request is processed, potentially disrupting critical network services and system availability. Since the vulnerability affects the kernel driver directly, the system crash can result in data loss, interrupted network connectivity, and potential service degradation that impacts business operations. The fact that this vulnerability can be exploited by local users means that it can be leveraged by malicious insiders or attackers who have already gained local access to a system, potentially escalating their privileges or causing persistent service disruption. The vulnerability also demonstrates poor defensive programming practices that violate fundamental security principles such as the principle of least privilege and proper input validation.
The mitigation strategy for this vulnerability requires immediate action from affected organizations, as there are no practical workarounds available. The most effective solution involves updating to a patched version of Look n Stop Firewall that properly validates IOCTL parameters and handles assertion failures gracefully. Organizations should also implement monitoring to detect potential exploitation attempts and consider restricting local user access to systems running vulnerable software. From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1068 Privilege Escalation through exploitation of kernel vulnerabilities, as local users could potentially leverage this flaw to gain elevated privileges or cause system instability. Additionally, the vulnerability demonstrates the importance of kernel-mode security testing and proper error handling in security software, as the flaw could have been prevented through better input validation and defensive programming practices. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of local privilege escalation attacks.