CVE-2010-3014 in FreeBSD
Summary
by MITRE
The Coda filesystem kernel module, as used in NetBSD and FreeBSD, when Coda is loaded and Venus is running with /coda mounted, allows local users to read sensitive heap memory via a large out_size value in a ViceIoctl struct to a Coda ioctl, which triggers a buffer over-read.
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Analysis
by VulDB Data Team • 01/07/2018
The vulnerability described in CVE-2010-3014 represents a critical buffer over-read flaw within the Coda filesystem kernel module implementation across NetBSD and FreeBSD operating systems. This issue specifically manifests when the Coda filesystem is actively loaded and the Venus user-space daemon is operating with the /coda mount point configured. The vulnerability stems from inadequate input validation within the ioctl handling mechanism of the kernel module, creating a pathway for local privilege escalation through memory disclosure attacks.
The technical exploitation of this vulnerability occurs through manipulation of the ViceIoctl structure during ioctl system calls to the Coda filesystem. When a local user provides an excessively large out_size parameter within this structure, the kernel module fails to properly validate the input boundaries before proceeding with memory operations. This validation failure results in a buffer over-read condition where the kernel attempts to read beyond allocated heap memory boundaries, potentially exposing sensitive information stored in adjacent memory regions. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, though in this specific case it manifests as a heap-based over-read due to the nature of the Coda filesystem memory management.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. An attacker could leverage the memory read capabilities to extract kernel memory contents including cryptographic keys, session tokens, or other sensitive data that might be stored in the heap memory regions. This information disclosure could facilitate further exploitation attempts, including privilege escalation or bypassing security mechanisms. The vulnerability affects systems where Coda filesystem is actively mounted and Venus is running, which represents a significant attack surface in distributed computing environments that rely on this filesystem implementation for file sharing across networked systems.
Mitigation strategies for CVE-2010-3014 require immediate system administration actions to address the root cause of the vulnerability. The primary recommendation involves applying kernel updates from NetBSD and FreeBSD security advisories that contain patches specifically addressing the input validation issues in the Coda filesystem ioctl handling. System administrators should also consider implementing runtime restrictions on Coda filesystem usage when not required for specific networked applications. Additionally, monitoring for suspicious ioctl calls with abnormal parameter values can help detect potential exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.003 for executing malicious code through kernel modules and T1003.001 for credential access through kernel memory manipulation. Organizations should also review their network configurations to minimize exposure of systems running Coda filesystem, particularly in environments where local user access cannot be fully trusted. The fix implemented in affected kernel versions typically involves adding proper bounds checking for the out_size parameter before memory operations are performed, ensuring that all memory access attempts remain within allocated buffer boundaries.