CVE-2010-4655 in Linux
Summary
by MITRE
net/core/ethtool.c in the Linux kernel before 2.6.36 does not initialize certain data structures, which allows local users to obtain potentially sensitive information from kernel heap memory by leveraging the CAP_NET_ADMIN capability for an ethtool ioctl call.
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Analysis
by VulDB Data Team • 07/01/2024
The vulnerability identified as CVE-2010-4655 resides within the Linux kernel's networking subsystem, specifically in the net/core/ethtool.c file. This flaw represents a classic information disclosure issue that occurs when kernel data structures are not properly initialized before being accessed through the ethtool interface. The vulnerability affects Linux kernel versions prior to 2.6.36 and requires an attacker to possess the CAP_NET_ADMIN capability, which is typically available to users with network administration privileges or root access. The issue stems from the kernel's failure to initialize memory structures that are subsequently exposed to userspace through ioctl system calls, creating a pathway for information leakage.
The technical implementation of this vulnerability involves the ethtool ioctl interface which provides a mechanism for network interface configuration and monitoring. When a user with CAP_NET_ADMIN capability makes an ethtool ioctl call, the kernel processes this request without properly initializing certain internal data structures. These uninitialized structures may contain remnants of previous data that was stored in the same memory locations, potentially including sensitive information from other kernel operations or previously processed network packets. This uninitialized memory exposure creates a scenario where local attackers can extract kernel heap memory contents through carefully crafted ethtool commands, effectively bypassing kernel memory protection mechanisms.
The operational impact of CVE-2010-4655 extends beyond simple information disclosure, as the leaked kernel memory may contain sensitive data such as cryptographic keys, network credentials, or other confidential information that could be exploited by attackers. This vulnerability aligns with CWE-119 which addresses improper access to memory and represents a specific instance of information exposure through uninitialized memory. The attack vector requires local access with network administration privileges, making it particularly concerning in environments where untrusted users might have such capabilities or where privilege escalation attacks could be mounted. The vulnerability demonstrates a fundamental security principle violation where kernel memory management fails to properly isolate sensitive information from potentially malicious userspace processes.
Security professionals should recognize this vulnerability as part of the broader ATT&CK framework's privilege escalation and defense evasion categories, where attackers leverage system interfaces to extract information that could aid in further exploitation. The recommended mitigation involves upgrading to Linux kernel version 2.6.36 or later, where the kernel developers addressed the uninitialized memory issue by properly initializing the affected data structures. Organizations should also implement proper privilege controls to limit access to CAP_NET_ADMIN capabilities and monitor for unauthorized ethtool usage patterns. Additional defensive measures include regular kernel updates, security auditing of network administration privileges, and implementation of kernel hardening techniques that can further reduce the attack surface. The vulnerability serves as a reminder of the critical importance of proper memory initialization in kernel space code and demonstrates how seemingly minor implementation oversights can create significant security risks in operating system components that are fundamental to system operation.