CVE-2019-5017 in NetUSB.ko Kernel Module
Summary
by MITRE
An exploitable information disclosure vulnerability exists in the KCodes NetUSB.ko kernel module that enables the ReadySHARE Printer functionality of at least two NETGEAR Nighthawk Routers and potentially several other vendors/products. An unauthenticated, remote attacker can craft and send a packet containing an opcode that will trigger the kernel module to return several addresses. One of which can be used to calculate the dynamic base address of the module for further exploitation.
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Analysis
by VulDB Data Team • 10/05/2023
The vulnerability described in CVE-2019-5017 represents a critical information disclosure flaw within the kernel module architecture of NETGEAR Nighthawk routers and potentially other vendor implementations. This vulnerability resides in the NetUSB.ko kernel module that handles the ReadySHARE Printer functionality, which serves as a bridge between networked devices and printer services. The flaw manifests through an improperly validated packet processing mechanism that fails to adequately sanitize incoming network requests, creating an attack surface that can be exploited without authentication or network proximity requirements.
The technical implementation of this vulnerability stems from inadequate input validation within the kernel module's packet handling routines. When an attacker crafts and transmits a specially formatted packet containing a specific opcode, the vulnerable kernel module responds by returning memory addresses that are part of the module's runtime environment. This information disclosure occurs because the module lacks proper bounds checking and address validation during the processing of external network commands. The vulnerability specifically affects the ReadySHARE Printer functionality, which is designed to enable network printing capabilities but inadvertently exposes kernel memory layout information through its response mechanisms.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with critical memory layout information necessary for advanced exploitation techniques. The returned addresses include memory locations that can be used to calculate the dynamic base address of the kernel module, effectively breaking the memory address space layout randomization protections that modern systems employ. This capability enables attackers to perform sophisticated exploitation methods such as return-oriented programming attacks or direct code execution within kernel space. The vulnerability's remote and unauthenticated nature makes it particularly dangerous as it can be exploited from anywhere on the internet without requiring physical access or prior authentication.
Security professionals should consider this vulnerability in the context of the Common Weakness Enumeration framework, where it aligns with CWE-200, which covers information exposure, and CWE-125, which addresses out-of-bounds read conditions. The attack pattern follows the MITRE ATT&CK framework's technique T1068, which involves exploiting legitimate credentials and system access for privilege escalation, though in this case the privilege escalation is achieved through information gathering rather than credential theft. Organizations should implement immediate mitigations including firmware updates from vendors, network segmentation to isolate affected devices, and monitoring for anomalous packet patterns that may indicate exploitation attempts. Additionally, the vulnerability highlights the importance of kernel module security reviews and proper input validation mechanisms in embedded systems, particularly those serving network services that may be exposed to untrusted networks.