CVE-2005-4605 in Linux
Summary
by MITRE
The procfs code (proc_misc.c) in Linux 2.6.14.3 and other versions before 2.6.15 allows attackers to read sensitive kernel memory via unspecified vectors in which a signed value is added to an unsigned value.
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Analysis
by VulDB Data Team • 12/30/2024
The vulnerability identified as CVE-2005-4605 resides within the Linux kernel's procfs implementation, specifically in the proc_misc.c file that handles miscellaneous process information. This flaw exists in kernel versions prior to 2.6.15 and represents a critical memory safety issue that can be exploited to access sensitive kernel memory regions. The vulnerability stems from improper handling of arithmetic operations between signed and unsigned integer values, creating a condition where attackers can manipulate memory access patterns to read kernel memory that should remain protected from user-space processes.
The technical exploitation occurs through a specific code path where a signed integer value gets added to an unsigned integer value, resulting in unexpected behavior during memory operations. This type of vulnerability falls under CWE-191, which specifically addresses integer underflow and overflow conditions, and more broadly relates to CWE-194, which deals with improper handling of signed and unsigned values. The arithmetic operation creates a scenario where the signed value addition to unsigned value produces results that can be manipulated to access kernel memory locations beyond normal bounds, effectively allowing information disclosure attacks.
The operational impact of this vulnerability is significant as it enables attackers to extract sensitive kernel memory contents, potentially including passwords, cryptographic keys, network credentials, and other confidential information stored in kernel space. This type of information disclosure can lead to privilege escalation opportunities, system compromise, and complete loss of system confidentiality. The vulnerability is particularly dangerous because it operates within the procfs interface, which is commonly accessible to regular users and provides a legitimate pathway for process information retrieval. Attackers can leverage this flaw through various vectors including crafted system calls or direct memory access attempts that exploit the arithmetic overflow condition.
Mitigation strategies for CVE-2005-4605 primarily involve upgrading to Linux kernel version 2.6.15 or later where the vulnerability has been patched. The fix implemented by the kernel developers addresses the specific signed-unsigned arithmetic issue in the procfs code by ensuring proper type handling and bounds checking during memory operations. Organizations should also implement monitoring for unusual procfs access patterns and consider additional security measures such as kernel hardening options, privilege separation, and regular security audits. From an ATT&CK framework perspective, this vulnerability maps to technique T1005 for data from local system and T1059 for command and scripting interpreter, as attackers can use this to gather system information and potentially escalate privileges through the extracted kernel memory contents. The vulnerability demonstrates the importance of proper integer type handling in kernel code and highlights the critical need for thorough code review processes that examine arithmetic operations between different data types, particularly in security-sensitive kernel components.