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ID

CWE-1270: Generation of Incorrect Security Tokens

Weakness ID: 1270
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The product implements a Security Token mechanism to differentiate what actions are allowed or disallowed when a transaction originates from an entity. However, the Security Tokens generated in the system are incorrect.
+ Extended Description

Systems-On-a-Chip (SoC) (Integrated circuits and hardware engines) implement Security Tokens to differentiate and identify actions originated from various agents. These actions could be "read", "write", "program", "reset", "fetch", "compute", etc. Security Tokens are generated and assigned to every agent on the SoC that is either capable of generating an action or receiving an action from another agent. Every agent could be assigned a unique, Security Token based on its trust level or privileges. Incorrectly generated Security Tokens could result in the same token used for multiple agents or multiple tokens being used for the same agent. This condition could result in a Denial-of-Service (DoS) or the execution of an action that in turn could result in privilege escalation or unintended access.

+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfPillarPillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.284Improper Access Control
+ Relevant to the view "Hardware Design" (CWE-1194)
NatureTypeIDName
ChildOfClassClass - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.1294Insecure Security Identifier Mechanism
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

Class: Language-Independent (Undetermined Prevalence)

Operating Systems

Class: OS-Independent (Undetermined Prevalence)

Architectures

Class: Architecture-Independent (Undetermined Prevalence)

Technologies

Class: Technology-Independent (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Confidentiality
Integrity
Availability
Access Control

Technical Impact: Modify Files or Directories; Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Gain Privileges or Assume Identity; Read Memory; Modify Memory; DoS: Crash, Exit, or Restart

High
+ Demonstrative Examples

Example 1

Consider a system with a register for storing an AES key for encryption or decryption. The key is 128 bits long implemented as a set of four 32-bit registers. The key registers are assets, and register, AES_KEY_ACCESS_POLICY, is defined to provide necessary access controls. The access-policy register defines which agents, using a Security Token, may access the AES-key registers. Each bit in this 32-bit register is used to define a Security Token. There could be a maximum of 32 Security Tokens that are allowed access to the AES-key registers. When set (bit = "1") bit number allows action from an agent whose identity matches that bit number. If Clear (bit = "0") the action is disallowed for the corresponding agent.

Let"s assume the system has two agents: a Main-controller and an Aux-controller. The respective Security Tokens are "1" and "2".

Register Description Default
AES_ENC_DEC_KEY_0 AES key [0:31] for encryption or decryption 0x00000000
AES_ENC_DEC_KEY_1 AES key [32:63] for encryption or decryption 0x00000000
AES_ENC_DEC_KEY_2 AES key [64:95] for encryption or decryption 0x00000000
AES_ENC_DEC_KEY_3 AES key [96:127] for encryption or decryption 0x00000000
AES_KEY_ACCESS_POLICY AES key access register [31:0] 0x00000002

An agent with a Security Token "1" has access to AES_ENC_DEC_KEY_0 through AES_ENC_DEC_KEY_3 registers. As per the above access policy, the AES-Key-access policy allows access to the AES-key registers if the security Token is "1".

(bad code)
Example Language: Other 
The SoC incorrectly generates Security Token "1" for every agent. In other words, both Main-controller and Aux-controller are assigned Security Token "1".

Both agents have access to the AES-key registers.

(good code)
Example Language: Other 
The SoC should correctly generate Security Tokens, assigning "1" to the Main-controller and "2" to the Aux-controller
+ Potential Mitigations

Phases: Architecture and Design; Implementation

  • Generation of Security Tokens should be reviewed for design inconsistency and common weaknesses.
  • Security-Token definition and programming flow should be tested in pre-silicon and post-silicon testing.
+ Content History
+ Submissions
Submission DateSubmitterOrganization
2020-03-06Arun Kanuparthi, Hareesh Khattri, Parbati Kumar Manna, Narasimha Kumar V MangipudiIntel Corporation
+ Modifications
Modification DateModifierOrganization
2020-08-20CWE Content TeamMITRE
updated Applicable_Platforms, Demonstrative_Examples, Description, Modes_of_Introduction, Name, Potential_Mitigations, Relationships
+ Previous Entry Names
Change DatePrevious Entry Name
2020-08-20Generation of Incorrect Security Identifiers
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Page Last Updated: August 20, 2020