CVE-2006-6657 in NetBSD
Summary
by MITRE
The if_clone_list function in NetBSD-current before 20061027, NetBSD 3.0 and 3.0.1 before 20061027, and NetBSD 2.x before 20061119 allows local users to read potentially sensitive, uninitialized stack memory via unspecified vectors.
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Analysis
by VulDB Data Team • 08/12/2018
The vulnerability described in CVE-2006-6657 represents a critical information disclosure flaw affecting multiple versions of the NetBSD operating system. This issue resides within the if_clone_list function which is responsible for managing network interface cloning operations within the kernel space. The vulnerability specifically impacts systems running NetBSD-current before October 27, 2006, NetBSD 3.0 and 3.0.1 before the same date, and NetBSD 2.x releases before November 19, 2006, creating a substantial attack surface across several major release lines.
The technical root cause of this vulnerability stems from improper memory initialization within the if_clone_list function where uninitialized stack memory is returned to userspace without proper sanitization. When local users exploit this flaw through unspecified vectors, they can access potentially sensitive data that remains in memory from previous operations or system states. This occurs because the function fails to clear or initialize stack variables before returning them to user processes, creating a classic information exposure vulnerability that falls under CWE-248. The uninitialized memory may contain remnants of passwords, cryptographic keys, system credentials, or other sensitive operational data that was previously stored in the same memory locations.
The operational impact of this vulnerability is significant for local attackers who can leverage it to gain unauthorized access to sensitive information that should remain protected within kernel memory spaces. This information disclosure can potentially lead to privilege escalation opportunities, credential harvesting, or further exploitation attempts against the system. The vulnerability's presence in multiple NetBSD versions indicates a widespread issue that affected numerous systems running these operating system releases, making it particularly dangerous in environments where these older versions remained in production use. The attack vector being unspecified suggests that various code paths within the if_clone_list function could trigger the information disclosure, making the vulnerability difficult to fully predict or defend against.
Organizations affected by this vulnerability should prioritize immediate patching of all impacted NetBSD systems to prevent exploitation. The recommended mitigation strategy involves updating to patched versions of NetBSD that address the uninitialized memory access issue in the if_clone_list function. System administrators should also implement monitoring for unusual network activity or memory access patterns that might indicate exploitation attempts. From a security framework perspective, this vulnerability aligns with ATT&CK technique T1005 for Data from Local System and T1059 for Command and Scripting Interpreter, as attackers could potentially use the leaked information to craft more sophisticated attacks against the compromised system. Additionally, this issue demonstrates the importance of proper memory management practices in kernel code, aligning with security best practices that emphasize the need for comprehensive input validation and memory sanitization to prevent information leakage through uninitialized memory access patterns.