CVE-2016-3156 in Linux
Summary
by MITRE
The IPv4 implementation in the Linux kernel before 4.5.2 mishandles destruction of device objects, which allows guest OS users to cause a denial of service (host OS networking outage) by arranging for a large number of IP addresses.
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Analysis
by VulDB Data Team • 07/27/2022
The vulnerability identified as CVE-2016-3156 represents a critical flaw in the Linux kernel's IPv4 implementation that affects versions prior to 4.5.2. This issue specifically targets the handling of device object destruction processes within the kernel's networking stack, creating a scenario where malicious actors can exploit the system's resource management mechanisms. The vulnerability operates through a sophisticated manipulation of IP address management that ultimately leads to system-wide networking disruption, making it particularly dangerous in virtualized environments where guest operating systems interact with host networking resources.
The technical flaw stems from improper handling of device object cleanup procedures when multiple IP addresses are configured on network interfaces. When a large number of IP addresses are created and subsequently destroyed, the kernel's reference counting mechanisms fail to properly account for all associated resources. This results in a memory management issue where device objects remain in memory even after they should have been fully released, causing a gradual depletion of available system resources. The vulnerability specifically manifests during the destruction phase of network device objects, where the kernel fails to properly traverse and clean up all associated data structures, leading to a cascade of resource exhaustion that ultimately impacts the entire host OS networking functionality.
The operational impact of CVE-2016-3156 extends beyond simple denial of service, as it creates a persistent resource leak that can be exploited by unprivileged users within guest operating systems to systematically degrade host system performance. In virtualized environments, this vulnerability allows attackers to consume host networking resources through legitimate network configuration operations, effectively creating a resource exhaustion attack that can render the entire host system unusable for network communications. The vulnerability is particularly concerning because it requires minimal privileges to exploit and can be triggered through normal network management operations, making it difficult to detect and prevent through standard security monitoring.
This vulnerability aligns with CWE-404, which describes improper resource management in software systems, and demonstrates characteristics consistent with the ATT&CK technique T1499.004 for network denial of service attacks. The exploitability of CVE-2016-3156 is enhanced in cloud and virtualization environments where multiple guest operating systems share host resources, making it a significant threat to infrastructure stability. The vulnerability's impact is amplified by its ability to cause cascading failures in network connectivity, affecting not just individual services but entire network operations within affected systems.
Mitigation strategies for CVE-2016-3156 require immediate kernel updates to versions 4.5.2 or later, where the memory management issues have been resolved through improved device object destruction handling. System administrators should also implement monitoring solutions that track network device object creation and destruction patterns to detect potential exploitation attempts. Additional protective measures include limiting the number of IP addresses that can be configured on network interfaces within virtualized environments and implementing resource quotas to prevent unbounded consumption of networking resources. The vulnerability highlights the importance of proper memory management in kernel space and demonstrates the critical need for thorough testing of resource cleanup procedures in operating system components that handle network operations.