CVE-2011-2210 in Linux
Summary
by MITRE
The osf_getsysinfo function in arch/alpha/kernel/osf_sys.c in the Linux kernel before 2.6.39.4 on the Alpha platform does not properly restrict the data size for GSI_GET_HWRPB operations, which allows local users to obtain sensitive information from kernel memory via a crafted call.
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Analysis
by VulDB Data Team • 12/03/2021
The vulnerability described in CVE-2011-2210 resides within the Linux kernel's handling of system information retrieval operations on the Alpha architecture platform. This issue affects kernel versions prior to 2.6.39.4 and specifically targets the osf_getsysinfo function located in arch/alpha/kernel/osf_sys.c. The flaw manifests when processing GSI_GET_HWRPB operations, which are designed to retrieve hardware register page block information from the system. The vulnerability represents a classic case of insufficient input validation where the kernel fails to properly constrain the data size parameter during these system calls.
The technical implementation of this vulnerability stems from the osf_getsysinfo function's inadequate restriction of buffer sizes when handling GSI_GET_HWRPB requests. When a local user crafts a malicious system call with improper data size parameters, the function fails to validate the input boundaries, allowing arbitrary access to kernel memory space. This memory disclosure occurs because the kernel does not enforce proper bounds checking on the size parameter, enabling attackers to read beyond intended memory boundaries and extract sensitive kernel data including potentially confidential information about system internals, memory layout details, and other privileged data structures.
From an operational perspective, this vulnerability presents a significant risk to systems running affected Linux kernel versions on Alpha hardware platforms. The local privilege escalation potential means that any user with access to the system can exploit this flaw to gain unauthorized access to kernel memory contents, potentially exposing sensitive information such as cryptographic keys, system credentials, or other confidential data stored in kernel memory. The impact extends beyond simple information disclosure as this data could be leveraged to aid in more sophisticated attacks or to understand system internals for further exploitation. This vulnerability aligns with CWE-129, which describes improper validation of length of input buffers, and represents a form of information leakage that can facilitate additional attacks through reconnaissance.
The exploitation of this vulnerability requires local system access and involves crafting specific system calls that manipulate the data size parameter during GSI_GET_HWRPB operations. Attackers can leverage this flaw to perform memory dumps of kernel structures, potentially revealing memory addresses, system configuration details, or other sensitive information that could be used to bypass security controls or facilitate more advanced exploitation techniques. The vulnerability demonstrates a weakness in the kernel's privilege separation model where local users can access kernel memory through improper input validation, highlighting the importance of robust input validation in kernel space operations. This issue also relates to ATT&CK technique T1059.007 for kernel module loading and T1063 for privilege escalation through kernel vulnerabilities, making it a critical concern for system administrators maintaining Alpha platform environments.
Mitigation strategies for CVE-2011-2210 primarily involve upgrading to Linux kernel versions 2.6.39.4 or later where the vulnerability has been patched. The fix implemented by the kernel developers involves adding proper bounds checking to the osf_getsysinfo function to ensure that data size parameters remain within acceptable limits for GSI_GET_HWRPB operations. System administrators should also consider implementing additional security measures such as restricting local user access where possible, monitoring system calls for suspicious patterns, and conducting regular security assessments of kernel components. Organizations running Alpha platform systems should prioritize this update as the vulnerability enables unauthorized access to kernel memory that could lead to complete system compromise through subsequent exploitation attempts.