CVE-2018-1059 in DPDK vhost-user interface
Summary
by MITRE
The DPDK vhost-user interface does not check to verify that all the requested guest physical range is mapped and contiguous when performing Guest Physical Addresses to Host Virtual Addresses translations. This may lead to a malicious guest exposing vhost-user backend process memory. All versions before 18.02.1 are vulnerable.
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Analysis
by VulDB Data Team • 01/31/2020
The vulnerability identified as CVE-2018-1059 affects the Data Plane Development Kit (DPDK) vhost-user interface, which is a critical component in virtualized networking environments where guest virtual machines communicate with host-based networking applications. This flaw resides in the memory management subsystem of the vhost-user implementation, specifically within the translation mechanism that maps guest physical addresses to host virtual addresses. The issue manifests when the vhost-user backend process performs address translation operations without properly validating the integrity of the guest physical memory ranges being accessed, creating a potential pathway for memory disclosure attacks.
The technical root cause of this vulnerability stems from insufficient validation during the Guest Physical Address (GPA) to Host Virtual Address (HVA) translation process. When a guest virtual machine requests memory access through the vhost-user interface, the backend process must verify that the entire requested physical memory range is properly mapped and contiguous in the guest's memory space. However, the vulnerable implementation fails to perform this crucial verification step, allowing a malicious guest to craft memory access requests that reference memory regions that are either unmapped or non-contiguous. This validation gap enables attackers to potentially access memory locations that should remain protected, including sensitive data from other processes or kernel memory regions.
The operational impact of this vulnerability extends beyond simple information disclosure, as it represents a significant security boundary violation that could enable attackers to gain unauthorized access to sensitive memory contents within the vhost-user backend process. Attackers could exploit this flaw to read arbitrary memory locations, potentially extracting confidential information such as cryptographic keys, user credentials, or other sensitive data stored in the backend process memory space. The vulnerability affects all DPDK versions prior to 18.02.1, making it particularly concerning for systems that have not been updated to address this memory management flaw. This type of vulnerability directly aligns with CWE-125, which describes out-of-bounds read conditions, and can be categorized under the ATT&CK technique T1005 for data from local system, as it allows for unauthorized memory access within the system.
The exploitation of this vulnerability typically requires a malicious guest virtual machine with access to the vhost-user interface, making it particularly dangerous in multi-tenant environments where guest isolation is critical for security. The attack vector involves the guest VM submitting memory access requests that bypass normal validation checks, potentially leading to memory disclosure or even privilege escalation if the backend process operates with elevated privileges. System administrators should consider implementing additional monitoring and access controls around vhost-user interfaces, as this vulnerability demonstrates the importance of proper input validation and memory boundary checking in hypervisor and virtualization components. The fix for this vulnerability in DPDK 18.02.1 involves implementing comprehensive validation of guest physical memory ranges before performing address translation operations, ensuring that all requested memory segments are properly mapped and contiguous within the guest's memory space.