CWE-1329: Reliance on Component That is Not Updateable

Description

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

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can be prone to this weakness, software systems can also be affected, such as when a third-party driver or library is no longer actively maintained or supported but is still critical for the required functionality.

Potential Impact

Demonstrative Examples

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

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

module dmi_jtag(...)(...);
					...
						
							
								
								PassChkValid: begin
								if(hashValid) begin
									
										
										if(exp_hash == pass_hash) begin
											 
											pass_check = 1'b1;
											
										end else begin
											
											pass_check = 1'b0;
											
										end
										state_d = Idle;
										
									end else begin
									state_d = PassChkValid;
									end
									
								end
								
							
						
					...
						
						hmac hmac(
						
					...
						
							
							.key_i(256'h24e6fa2254c2ff632a41b...),
							
						
					...
						
						);
						
					...
					endmodule

module dmi_jtag(...
					) (
						
						input logic [255:0] hmac_key_i,
						input logic         hmac_patch_en,
						... 
						reg [255:0] hmac_key_reg;
						...
						
					);
					...
						
						always_ff @(posedge tck_i or negedge trst_ni) begin
						...
						if (hmac_patch_en)
							
							hmac_key_reg <= hmac_key_i;
							
						...
						end
						
					...
						
						hmac hmac(
						...
						.key_i(hmac_key_reg),
						...
						);
						
					...
					endmodule

Mitigations & Prevention

Detection Methods

• Architecture or Design Review Moderate — 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.

Real-World CVE Examples

Related Weaknesses