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Common Weakness Enumeration

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ID

CWE-1302: Missing Security Identifier

Weakness ID: 1302
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The product implements a security identifier mechanism to differentiate what actions are allowed or disallowed when a transaction originates from an entity. A transaction is sent without a security identifier.
+ Extended Description

In a System-On-Chip (SoC), various integrated circuits and hardware engines generate transactions such as to access (reads/writes) assets or perform certain actions (e.g., reset, fetch, compute). A typical transaction is comprised of source identity (to identify the originator of the transaction) and a destination identity (to route the transaction to the respective entity) in addition to much more information in the message. Sometimes the transactions are qualified with a Security Identifier. This Security Identifier helps the destination agent decide on the set of allowed or disallowed actions.

A common weakness that can exist in such transaction schemes is that the source agent fails to include the necessary, security identifier with the transaction. Because of the missing security identifier, the destination agent might drop the message, thus resulting in Denial-of-Service (DoS), or get confused in its attempt to execute the given action, which confusion could result in privilege escalation or a gain of 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
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
+ Relevant to the view "Hardware Design" (CWE-1194)
NatureTypeIDName
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.1198Privilege Separation and Access Control Issues
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.1201Core and Compute Issues
+ 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 DesignSuch issues could be introduced during hardware architecture and design and identified later during Testing or System Configuration phases.
ImplementationSuch issues could be introduced during implementation and identified later during Testing or System Configuration phases.
+ 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 Memory; Read Memory; DoS: Crash, Exit, or Restart; Bypass Protection Mechanism; Execute Unauthorized Code or Commands

High
+ Demonstrative Examples

Example 1

Consider a system with a register for storing AES key for encryption or decryption. The key is of 128 bits implemented as a set of four 32-bit registers. The key registers are assets, and the register AES_KEY_ACCESS_POLICY is defined to provide the necessary access controls.

The access-policy register defines which agents with a security identifier in the transaction can access the AES-key registers. Each bit in this 32-bit register defines a security identifier. There could be a maximum of 32 security identifiers that are allowed accesses to the AES-key registers. The number of the bit when set (i.e., “1”) allows for a respective action from an agent whose identity matches the number of the bit; if set to “0” (i.e., Clear), it disallows the respective action to that corresponding agent.

(bad code)
 
Register Field description
AES_ENC_DEC_KEY_0 AES key [0:31] for encryption or decryption, Default 0x00000000
AES_ENC_DEC_KEY_1 AES key [32:63] forencryption or decryption, Default 0x00000000
AES_ENC_DEC_KEY_2 AES key [64:95] for encryption or decryption, Default 0x00000000
AES_ENC_DEC_KEY_4 AES key [96:127] for encryption or decryption, Default 0x00000000
AES_KEY_ACCESS_POLICY [31:0] Default 0x00000004 – agent with Security Identifier “2” has access to AES_ENC_DEC_KEY_0 through AES_ENC_DEC_KEY_4 registers

The originator sends a transaction with no security identifier, i.e., meaning the value is “0” or NULL. The AES-Key-access register does not allow the necessary action and drops the transaction because the originator failed to include the required security identifier.

(good code)
 
Register Field description
AES_ENC_DEC_KEY_0 AES key [0:31] for encryption or decryption, Default 0x00000000
AES_ENC_DEC_KEY_1 AES key [32:63] forencryption or decryption, Default 0x00000000
AES_ENC_DEC_KEY_2 AES key [64:95] for encryption or decryption, Default 0x00000000
AES_ENC_DEC_KEY_4 AES key [96:127] for encryption or decryption, Default 0x00000000
AES_KEY_ACCESS_POLICY [31:0] Default 0x00000002 – agent with security identifier “2” has access to AES_ENC_DEC_KEY_0 through AES_ENC_DEC_KEY_4 registers

The originator should send a transaction with Security Identifier “2” which will allow access to the AES-Key-access register and allow encryption and decryption operations.

+ Potential Mitigations

Phase: Architecture and Design

Transaction details must be reviewed for design inconsistency and common weaknesses.

Phase: Implementation

Security identifier definition and programming flow must be tested in pre-silicon and post-silicon testing.
+ Content History
+ Submissions
Submission DateSubmitterOrganization
2020-02-14Arun Kanuparthi, Hareesh Khattri, Parbati Kumar MannaIntel Corporation
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Page Last Updated: August 20, 2020