T1499.001 OS Exhaustion Flood Mappings

Adversaries may target the operating system (OS) for a DoS attack, since the (OS) is responsible for managing the finite resources on a system. These attacks do not need to exhaust the actual resources on a system since they can simply exhaust the limits that an OS self-imposes to prevent the entire system from being overwhelmed by excessive demands on its capacity.

Different ways to achieve this exist, including TCP state-exhaustion attacks such as SYN floods and ACK floods.(Citation: Arbor AnnualDoSreport Jan 2018) With SYN floods, excessive amounts of SYN packets are sent, but the 3-way TCP handshake is never completed. Because each OS has a maximum number of concurrent TCP connections that it will allow, this can quickly exhaust the ability of the system to receive new requests for TCP connections, thus preventing access to any TCP service provided by the server.(Citation: Cloudflare SynFlood)

ACK floods leverage the stateful nature of the TCP protocol. A flood of ACK packets are sent to the target. This forces the OS to search its state table for a related TCP connection that has already been established. Because the ACK packets are for connections that do not exist, the OS will have to search the entire state table to confirm that no match exists. When it is necessary to do this for a large flood of packets, the computational requirements can cause the server to become sluggish and/or unresponsive, due to the work it must do to eliminate the rogue ACK packets. This greatly reduces the resources available for providing the targeted service.(Citation: Corero SYN-ACKflood)

View in MITRE ATT&CK®

Mappings

Capability ID Capability Description Mapping Type ATT&CK ID ATT&CK Name
AC-3 Access Enforcement Protects T1499.001 OS Exhaustion Flood
AC-4 Information Flow Enforcement Protects T1499.001 OS Exhaustion Flood
CA-7 Continuous Monitoring Protects T1499.001 OS Exhaustion Flood
CM-6 Configuration Settings Protects T1499.001 OS Exhaustion Flood
CM-7 Least Functionality Protects T1499.001 OS Exhaustion Flood
SC-7 Boundary Protection Protects T1499.001 OS Exhaustion Flood
SI-10 Information Input Validation Protects T1499.001 OS Exhaustion Flood
SI-15 Information Output Filtering Protects T1499.001 OS Exhaustion Flood
SI-4 System Monitoring Protects T1499.001 OS Exhaustion Flood
azure_security_center_recommendations Azure Security Center Recommendations technique_scores T1499.001 OS Exhaustion Flood
network_security_groups Network Security Groups technique_scores T1499.001 OS Exhaustion Flood
azure_private_link Azure Private Link technique_scores T1499.001 OS Exhaustion Flood
azure_ddos_protection_standard Azure DDOS Protection Standard technique_scores T1499.001 OS Exhaustion Flood
azure_network_traffic_analytics Azure Network Traffic Analytics technique_scores T1499.001 OS Exhaustion Flood