CVE-2008-0324 in VPN Client
Summary
by MITRE
Cisco Systems VPN Client IPSec Driver (CVPNDRVA.sys) 5.0.02.0090 allows local users to cause a denial of service (crash) by calling the 0x80002038 IOCTL with a small size value, which triggers memory corruption.
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Analysis
by VulDB Data Team • 10/14/2024
The vulnerability identified as CVE-2008-0324 affects the Cisco Systems VPN Client IPSec Driver component known as CVPNDRVA.sys version 5.0.02.0090. This represents a critical local privilege escalation issue that can be exploited to cause system instability and denial of service conditions. The vulnerability resides within the kernel-mode driver responsible for handling IPSec VPN connections, making it particularly dangerous as it operates with elevated privileges and can directly impact system stability. The flaw manifests through improper input validation within the driver's IOCTL handling mechanism, specifically when processing the 0x80002038 command code.
The technical exploitation of this vulnerability involves a local attacker who can craft a malicious IOCTL call with an intentionally small size parameter to the vulnerable driver. This specific IOCTL code 0x80002038 represents a function call that the driver does not properly validate before processing, leading to memory corruption issues. When the driver receives this malformed input, it attempts to allocate or access memory regions based on the invalid size parameter, resulting in buffer overflows or memory access violations that ultimately crash the system. The vulnerability is classified as a memory corruption issue that can be leveraged to achieve arbitrary code execution or system termination, making it a significant concern for enterprise environments relying on Cisco VPN solutions.
From an operational perspective, this vulnerability presents a substantial risk to organizations using legacy Cisco VPN client implementations. The local nature of the exploit means that any user with access to the system can potentially trigger the denial of service condition, which can be particularly problematic in shared or multi-user environments. The impact extends beyond simple system crashes as it can disrupt critical business operations, especially in scenarios where VPN connectivity is essential for remote access or network operations. The vulnerability can be exploited without requiring network access or authentication, making it particularly dangerous as it can be triggered by any local user regardless of their privilege level. This characteristic aligns with attack patterns documented in the MITRE ATT&CK framework under the privilege escalation and denial of service tactics.
The underlying cause of this vulnerability can be traced to inadequate input validation and memory management practices within the driver code. According to CWE classification, this represents a CWE-125: Out-of-bounds Read vulnerability that occurs when the driver fails to properly validate input parameters before using them in memory operations. The improper handling of IOCTL parameters without sufficient bounds checking creates an environment where malicious inputs can cause memory corruption. Organizations should consider implementing multiple layers of defense including regular patching of vulnerable software components, network segmentation to limit local access, and monitoring for suspicious IOCTL activity. The vulnerability also highlights the importance of proper driver security practices and input validation as recommended by the National Institute of Standards and Technology cybersecurity frameworks, particularly in environments where legacy software continues to operate without proper security updates.