Modify On-Board Values: Watchdog Timer (WDT)

Threat actors may manipulate the WDT for several reasons including the manipulation of timeout values which could enable processes to run without interference - potentially depleting on-board resources. For spacecraft, WDTs can be either software or hardware. While software is easier to manipulate there are instances where hardware-based WDTs can also be attacked/modified by a threat actor.

ID: CM0044
Sub-technique of:  EX-0012
Related Aerospace Threat IDs:  SV-AV-2 | SV-AV-3 | SV-IT-2 | SV-SP-9
Related MITRE ATT&CK TTPs: 
Tactic:
Created: 2022/10/19
Last Modified: 2022/10/28

Countermeasures

ID Name Description NIST Rev5 D3FEND ISO 27001
CM0069 Process White Listing Simple process ID whitelisting on the firmware level could impede attackers from instigating unnecessary processes which could impact the spacecraft CM-7(5) SI-10(5) A.8.19
CM0032 On-board Intrusion Detection & Prevention Utilize on-board intrusion detection/prevention system that monitors the mission critical components or systems and audit/logs actions. The IDS/IPS should have the capability to respond to threats and it should address signature-based attacks along with dynamic never-before seen attacks using machine learning/adaptive technologies. The IDS/IPS must integrate with traditional fault management to provide a wholistic approach to faults on-board the spacecraft. Spacecraft should select and execute safe countermeasures against cyber-attacks.  These countermeasures are a ready supply of options to triage against the specific types of attack and mission priorities. Minimally, the response should ensure vehicle safety and continued operations. Ideally, the goal is to trap the threat, convince the threat that it is successful, and trace and track the attacker — with or without ground support. This would support successful attribution and evolving countermeasures to mitigate the threat in the future. “Safe countermeasures” are those that are compatible with the system’s fault management system to avoid unintended effects or fratricide on the system. AU-14 AU-2 AU-3 AU-3(1) AU-4 AU-4(1) AU-5 AU-5(2) AU-5(5) AU-6(1) AU-6(4) AU-8 AU-9 AU-9(2) AU-9(3) CA-7(6) CM-11(3) CP-10 CP-10(4) IR-4 IR-4(11) IR-4(12) IR-4(14) IR-5 IR-5(1) RA-10 RA-3(4) SA-8(21) SA-8(22) SA-8(23) SC-16(2) SC-32(1) SC-5(3) SC-7(9) SI-10(6) SI-16 SI-17 SI-4 SI-4(10) SI-4(11) SI-4(16) SI-4(2) SI-4(25) SI-4(4) SI-4(5) SI-6 SI-7(17) SI-7(8) A.8.15 A.8.15 A.8.6 A.8.17 A.5.33 A.8.15 A.8.15 A.5.29 A.5.25 A.5.26 A.5.27 A.5.7 A.8.16 A.8.16 A.8.16
CM0042 Robust Fault Management Ensure fault management system cannot be used against the spacecraft. Examples include: safe mode with crypto bypass, orbit correction maneuvers, affecting integrity of telemetry to cause action from ground, or some sort of proximity operation to cause spacecraft to go into safe mode. Understanding the safing procedures and ensuring they do not put the spacecraft in a more vulnerable state is key to building a resilient spacecraft. CP-4(5) SA-8(24) SC-16(2) SC-24 SI-13 SI-17
CM0044 Cyber-safe Mode Provide the capability to enter the spacecraft into a configuration-controlled and integrity-protected state representing a known, operational cyber-safe state (e.g., cyber-safe mode). Spacecraft should enter a cyber-safe mode when conditions that threaten the platform are detected.   Cyber-safe mode is an operating mode of a spacecraft during which all nonessential systems are shut down and the spacecraft is placed in a known good state using validated software and configuration settings. Within cyber-safe mode, authentication and encryption should still be enabled. The spacecraft should be capable of reconstituting firmware and software functions to pre-attack levels to allow for the recovery of functional capabilities. This can be performed by self-healing, or the healing can be aided from the ground. However, the spacecraft needs to have the capability to replan, based on equipment still available after a cyber-attack. The goal is for the spacecraft to resume full mission operations. If not possible, a reduced level of mission capability should be achieved. Cyber-safe mode software/configuration should be stored onboard the spacecraft in memory with hardware-based controls and should not be modifiable.                                                  CP-10 CP-10(4) CP-12 CP-2(5) IR-4 IR-4(12) IR-4(3) SA-8(21) SA-8(23) SA-8(24) SC-16(2) SC-24 SI-11 SI-17 SI-7(17) A.5.29 A.5.25 A.5.26 A.5.27

References