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Reliance on Component That is Not Updateable

Incomplete Base
Structure: Simple
Description

The product contains a component that cannot be updated or patched in order to remove vulnerabilities or significant bugs.

Extended Description

If the component is discovered to contain a vulnerability or critical bug, but the issue cannot be fixed using an update or patch, then the product's owner will not be able to protect against the issue. The only option might be replacement of the product, which could be too financially or operationally expensive for the product owner. As a result, the inability to patch or update can leave the product open to attacker exploitation or critical operation failures. This weakness can be especially difficult to manage when using ROM, firmware, or similar components that traditionally have had limited or no update capabilities. In industries such as healthcare, "legacy" devices can be operated for decades. As a US task force report [REF-1197] notes, "the inability to update or replace equipment has both large and small health care delivery organizations struggle with numerous unsupported legacy systems that cannot easily be replaced (hardware, software, and operating systems) with large numbers of vulnerabilities and few modern countermeasures." While hardware can be prone to this weakness, software systems can also be affected, such as when a third-party driver or library is no longer actively maintained or supported but is still critical for the required functionality.

Common Consequences 1
Scope: ConfidentialityIntegrityAccess ControlAuthenticationAuthorizationOther

Impact: Gain Privileges or Assume IdentityBypass Protection MechanismExecute Unauthorized Code or CommandsDoS: Crash, Exit, or RestartQuality DegradationReduce Maintainability

If an attacker can identify an exploitable vulnerability in one product that has no means of patching, the attack may be used against all affected versions of that product.
Detection Methods 1
Architecture or Design ReviewModerate
Check the consumer or maintainer documentation, the architecture/design documentation, or the original requirements to ensure that the documentation includes details for how to update the firmware.
Potential Mitigations 4
Phase: Requirements
Specify requirements that each component should be updateable, including ROM, firmware, etc.
Phase: Architecture and Design
Design the product to allow for updating of its components. Include the external infrastructure that might be necessary to support updates, such as distribution servers.
Phase: Architecture and DesignImplementation
With hardware, support patches that can be programmed in-field or during manufacturing through hardware fuses. This feature can be used for limited patching of devices after shipping, or for the next batch of silicon devices manufactured, without changing the full device ROM.

Effectiveness: Moderate

Phase: Implementation
Implement the necessary functionality to allow each component to be updated.
Demonstrative Examples 3

ID : DX-145

A refrigerator has an Internet interface for the official purpose of alerting the manufacturer when that refrigerator detects a fault. Because the device is attached to the Internet, the refrigerator is a target for hackers who may wish to use the device other potentially more nefarious purposes.

Code Example:

Bad
Other

The refrigerator has no means of patching and is hacked becoming a spewer of email spam.

Code Example:

Good
Other

The device automatically patches itself and provides considerable more protection against being hacked.

ID : DX-146

A System-on-Chip (SOC) implements a Root-of-Trust (RoT) in ROM to boot secure code. However, at times this ROM code might have security vulnerabilities and need to be patched. Since ROM is immutable, it can be impossible to patch.
ROM does not have built-in application-programming interfaces (APIs) to patch if the code is vulnerable. Implement mechanisms to patch the vulnerable ROM code.
The example code is taken from the JTAG module of the buggy OpenPiton SoC of HACK@DAC'21. JTAG is protected with a password checker. Access to JTAG operations will be denied unless the correct password is provided by the user. This user-provided password is first sent to the HMAC module where it is hashed with a secret crypto key. This user password hash (pass_hash) is then compared with the hash of the correct password (exp_hash). If they match, JTAG will then be unlocked.

Code Example:

Bad
Verilog

module dmi_jtag(...)(...); ...

verilog

.key_i(256'h24e6fa2254c2ff632a41b...),** ...

verilog
However, the SoC's crypto key is hardcoded into the design and cannot be updated [REF-1387]. Therefore, if the key is leaked somehow, there is no way to reprovision the key without having the device replaced.
To fix this issue, a local register should be used (hmac_key_reg) to store the crypto key. If designers need to update the key, they can upload the new key through an input port (hmac_key_i) to the local register by enabling the patching signal (hmac_patch_en) [REF-1388].

Code Example:

Good
Verilog

module dmi_jtag(... ) (



input logic [255:0] hmac_key_i,**


verilog


...


verilog


if (hmac_patch_en)**


verilog


verilog


verilog


verilog
  
Observed Examples 1
CVE-2020-9054Chain: network-attached storage (NAS) device has a critical OS command injection (Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) vulnerability that is actively exploited to place IoT devices into a botnet, but some products are "end-of-support" and cannot be patched (Firmware Not Updateable). [REF-1097]
  
References 4
Report on Improving Cybersecurity in the
			Health Care Industry
Health Care Industry Cybersecurity Task Force
06-2017
https://www.phe.gov/Preparedness/planning/CyberTF/Documents/report2017.pdf
ID: REF-1197
Zyxel Flaw Powers New Mirai IoT Botnet Strain
Brian Krebs
20-03-2020
https://krebsonsecurity.com/2020/03/zxyel-flaw-powers-new-mirai-iot-botnet-strain/
ID: REF-1097
dmi_jtag.sv line 324
2021
https://github.com/HACK-EVENT/hackatdac21/blob/main/piton/design/chip/tile/ariane/src/riscv-dbg/src/dmi_jtag.sv#L324C9-L324C87(2024-01-16)
ID: REF-1387
Fix for dmi_jtag.sv
2021
https://github.com/HACK-EVENT/hackatdac21/commit/c94ce5f9487a41c77ede0bbc8daf4da66c39f42a(2024-01-16)
ID: REF-1388
 
  
    
 
 
Applicable Platforms 
 
 
 
 
 
Languages:
 
 
 Not Language-Specific : Undetermined 
 
 
Technologies:
 
 
 Not Technology-Specific : UndeterminedICS/OT : Undetermined 
 
 
 
  
 
 
Modes of Introduction 
 
 
 
 
 
  Requirements  
 
  Architecture and Design  
 
  Architecture and Design  
 
  Implementation  
 
 
 
          
 
 
Related Weaknesses 
 
 
 
 
  ChildOf:
 Reliance on Insufficiently Trustworthy Component (CWE-1357) 
  ChildOf:
 Reliance on Insufficiently Trustworthy Component (CWE-1357) 
  ChildOf:
 Improper Control of a Resource Through its Lifetime (CWE-664)