The System-On-A-Chip (SoC) implements a Security Token mechanism to differentiate what actions are allowed or disallowed when a transaction originates from an entity. However, the Security Tokens are improperly protected.
View on MITRESystems-On-A-Chip (Integrated circuits and hardware engines) implement Security Tokens to differentiate and identify which actions originated from which agent. These actions may be one of the directives: 'read', 'write', 'program', 'reset', 'fetch', 'compute', etc. Security Tokens are assigned to every agent in the System that is capable of generating an action or receiving an action from another agent. Multiple Security Tokens may be assigned to an agent and may be unique based on the agent's trust level or allowed privileges. Since the Security Tokens are integral for the maintenance of security in an SoC, they need to be protected properly. A common weakness afflicting Security Tokens is improperly restricting the assignment to trusted components. Consequently, an improperly protected Security Token may be able to be programmed by a malicious agent (i.e., the Security Token is mutable) to spoof the action as if it originated from a trusted agent.
Security Token assignment review checks for design inconsistency and common weaknesses. Security-Token definition and programming flow is tested in both pre-silicon and post-silicon testing.
No detection method information available for this CWE.
For example, consider a system with a register for storing an AES key for encryption and decryption. The key is of 128 bits implemented as a set of four 32-bit registers. The key register assets have an associated control register, AES_KEY_ACCESS_POLICY, which provides the necessary access controls. This access-policy register defines which agents may engage in a transaction, and the type of transaction, with the AES-key registers. Each bit in this 32-bit register defines a security Token. There could be a maximum of 32 security Tokens that are allowed access to the AES-key registers. The number of the bit when set (i.e., "1") allows respective action from an agent whose identity matches the number of the bit and, if "0" (i.e., Clear), disallows the respective action to that 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
For example, consider a system with a register for storing an AES key for encryption and decryption. The key is of 128 bits implemented as a set of four 32-bit registers. The key register assets have an associated control register, AES_KEY_ACCESS_POLICY, which provides the necessary access controls. This access-policy register defines which agents may engage in a transaction, and the type of transaction, with the AES-key registers. Each bit in this 32-bit register defines a security Token. There could be a maximum of 32 security Tokens that are allowed access to the AES-key registers. The number of the bit when set (i.e., "1") allows respective action from an agent whose identity matches the number of the bit and, if "0" (i.e., Clear), disallows the respective action to that 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
No relationship information available for this CWE.
CWE-1259: Improper Restriction of Security Token Assignment is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The System-On-A-Chip (SoC) implements a Security Token mechanism to differentiate what actions are allowed or disallowed when a transaction originates from an entity. However, the Security Tokens are improperly protected. Systems-On-A-Chip (Integrated circuits and hardware engines) implement Security Tokens to differentiate and identify which actions originated from which agent. These actions may be one of the directives: 'read', 'write', 'program', 'reset', 'fetch', 'compute', etc. Security Tokens are assigned to every agent in the System that is capable of generating an action or receiving an action from another agent. Multiple Security Tokens may be assigned to an agent and may be unique based on the agent's trust level or allowed privileges. Since the Security Tokens are integral for the maintenance of security in an SoC, they need to be protected properly. A common weakness afflicting Security Tokens is improperly restricting the assignment to trusted components. Consequently, an improperly protected Security Token may be able to be programmed by a malicious agent (i.e., the Security Token is mutable) to spoof the action as if it originated from a trusted agent.
If exploited, CWE-1259 (Improper Restriction of Security Token Assignment) it can compromise Confidentiality, Integrity, Availability and Access Control, leading to outcomes such as Modify Files or Directories, Execute Unauthorized Code or Commands, Bypass Protection Mechanism, Gain Privileges or Assume Identity, Modify Memory and DoS: Crash, Exit, or Restart.
Recommended mitigations for CWE-1259 include: Security Token assignment review checks for design inconsistency and common weaknesses. Security-Token definition and programming flow is tested in both pre-silicon and post-silicon testing.
CWE-1259 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
A CWE (Common Weakness Enumeration) like CWE-1259 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.