CWE-1223
Alerte pour un CWE
Race Condition for Write-Once Attributes
Extended Description
Integrated circuits and hardware IP software programmable controls and settings are commonly stored in register circuits. These register contents have to be initialized at hardware reset to defined default values that are hard coded in the hardware description language (HDL) code of the hardware unit. A common security protection method used to protect register settings from modification by software is to make them write-once. This means the hardware implementation only allows writing to such registers once, and they become read-only after having been written once by software. This is useful to allow initial boot software to configure systems settings to secure values while blocking runtime software from modifying such hardware settings.
Implementation issues in hardware design of such controls can expose such registers to a race condition security flaw. For example, consider a hardware design that has two different software/firmware modules executing in parallel. One module is trusted (module A) and another is untrusted (module B). In this design it could be possible for Module B to send write cycles to the write-once register before Module A. Since the field is write-once the programmed value from Module A will be ignored and the pre-empted value programmed by Module B will be used by hardware.
Informations
Modes Of Introduction
Architecture and Design : This weakness can appear in designs that use register write-once attributes with two or more software/firmware modules with varying levels of trust executing in parallel.Applicable Platforms
Language
Name: Verilog (Undetermined)Name: VHDL (Undetermined)
Technologies
Class: System on Chip (Undetermined)Common Consequences
| Scope | Impact | Likelihood |
|---|---|---|
| Access Control | Bypass Protection Mechanism Note: System configuration cannot be programmed in a secure way. |
Potential Mitigations
Phases : Architecture and DesignDuring hardware design all register write-once or sticky fields must be evaluated for proper configuration.
Phases : Testing
The testing phase should use automated tools to test that values are not reprogrammable and that write-once fields lock on writing zeros.
Vulnerability Mapping Notes
Rationale : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.Comments : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
Related Attack Patterns
| CAPEC-ID | Attack Pattern Name |
|---|---|
| CAPEC-26 | Leveraging Race Conditions The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file. |
Submission
| Name | Organization | Date | Date Release | Version |
|---|---|---|---|---|
| Arun Kanuparthi, Hareesh Khattri, Parbati Kumar Manna, Narasimha Kumar V Mangipudi | Intel Corporation | 4.0 |
Modifications
| Name | Organization | Date | Comment |
|---|---|---|---|
| CWE Content Team | MITRE | updated Related_Attack_Patterns | |
| CWE Content Team | MITRE | updated Demonstrative_Examples | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Mapping_Notes |
