CVE-2007-2878 in Linux
Summary
by MITRE
The VFAT compat ioctls in the Linux kernel before 2.6.21.2, when run on a 64-bit system, allow local users to corrupt a kernel_dirent struct and cause a denial of service (system crash) via unknown vectors.
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Analysis
by VulDB Data Team • 12/22/2024
The vulnerability identified as CVE-2007-2878 represents a critical kernel-level flaw affecting Linux systems running versions prior to 2.6.21.2, particularly on 64-bit architectures. This issue resides within the VFAT filesystem compatibility ioctls implementation, which serves as an interface for legacy filesystem operations. The vulnerability stems from improper handling of kernel_dirent structures during ioctl operations, creating a potential pathway for local privilege escalation and system instability. The flaw manifests when the kernel processes certain ioctl commands related to VFAT filesystem compatibility, specifically under 64-bit system configurations where data structure alignment and memory management differ significantly from 32-bit environments.
The technical exploitation of this vulnerability involves manipulating the kernel_dirent struct through malformed ioctl calls, which can result in memory corruption within kernel space. This corruption leads to unpredictable behavior including system crashes, kernel panics, and complete system denial of service. The vulnerability is particularly dangerous because it operates at the kernel level where memory corruption can lead to arbitrary code execution or system compromise. The issue is specifically tied to 64-bit systems due to differences in data structure sizes and memory alignment requirements between 32-bit and 64-bit kernel architectures. This represents a classic case of buffer overflow or memory corruption vulnerability that can be exploited through improper input validation in kernel space drivers.
From an operational perspective, this vulnerability poses significant risks to Linux systems deployed in production environments where stability and uptime are critical. Local users with minimal privileges can exploit this flaw to cause system crashes, potentially leading to service disruption and denial of service conditions. The impact extends beyond simple system crashes as such vulnerabilities can serve as stepping stones for more sophisticated attacks, especially when combined with other kernel-level vulnerabilities. The vulnerability affects systems running older kernel versions where security patches have not been applied, making it particularly concerning for organizations maintaining legacy systems or those with delayed patch management processes. This vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and can be mapped to ATT&CK technique T1068, involving exploitation of remote services or local system vulnerabilities.
Mitigation strategies for CVE-2007-2878 focus primarily on kernel version updates and patch management. Organizations should immediately upgrade to Linux kernel versions 2.6.21.2 or later where this vulnerability has been addressed through proper input validation and memory management in the VFAT compatibility ioctls implementation. System administrators should implement comprehensive patch management policies to ensure all kernel components receive timely security updates. Additional protective measures include restricting local user access to system resources where possible, implementing proper access controls, and monitoring for unusual system behavior that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of kernel security testing and validation, particularly for compatibility layers that interface with legacy filesystem implementations. Security teams should conduct regular vulnerability assessments of kernel components and maintain awareness of known issues affecting their specific kernel versions to prevent exploitation of similar vulnerabilities in the future.