CWE-1315 Base Incomplet

Improper Setting of Bus Controlling Capability in Fabric End-point

This vulnerability occurs when a hardware fabric endpoint is incorrectly configured to grant bus controller privileges to a device that should only respond to requests. This allows an unauthorized…

Définition

What is CWE-1315?

This vulnerability occurs when a hardware fabric endpoint is incorrectly configured to grant bus controller privileges to a device that should only respond to requests. This allows an unauthorized device to initiate and control data transactions across the system bus.
Many modern system-on-chip (SoC) designs use reusable fabric endpoints with a configurable control bit. This bit determines whether a connected IP block (like a peripheral) can act only as a responder to requests, or if it can also act as a controller, initiating transactions to access other system components. While this flexibility aids hardware reuse, it introduces a critical security boundary. If this control bit is enabled by default in the hardware design, or if system firmware or software incorrectly sets it during operation, a peripheral intended to be passive gains unauthorized control over the system fabric. This compromised device can then read from or write to sensitive memory regions or other peripherals, leading to data exposure, privilege escalation, or a complete system takeover.
Impact réel

Real-world CVEs caused by CWE-1315

Aucune référence CVE publique n'est liée à ce CWE dans le catalogue MITRE pour le moment.

Comment les attaquants l'exploitent

Parcours de l'attaquant étape par étape

  1. 1

    A typical, phone platform consists of the main, compute core or CPU, a DRAM-memory chip, an audio codec, a baseband modem, a power-management-integrated circuit ("PMIC"), a connectivity (WiFi and Bluetooth) modem, and several other analog/RF components. The main CPU is the only component that can control transactions, and all the other components are responder-only devices. All the components implement a PCIe end-point to interface with the rest of the platform. The responder devices should have the bus-control-enable bit in the PCIe-end-point register set to 0 in hardware to prevent the devices from controlling transactions to the CPU or other peripherals.

  2. 2

    The audio-codec chip does not have the bus-controller-enable-register bit hardcoded to 0. There is no platform-firmware flow to verify that the bus-controller-enable bit is set to 0 in all responders.

  3. 3

    Audio codec can now master transactions to the CPU and other platform components. Potentially, it can modify assets in other platform components to subvert system security.

  4. 4

    Platform firmware includes a flow to check the configuration of bus-controller-enable bit in all responder devices. If this register bit is set on any of the responders, platform firmware sets it to 0. Ideally, the default value of this register bit should be hardcoded to 0 in RTL. It should also have access control to prevent untrusted entities from setting this bit to become bus controllers.

Exemple de code vulnérable

Vulnerable pseudo

MITRE n'a pas publié d'exemple de code pour ce CWE. Le motif ci-dessous est illustratif — voir Ressources pour les références canoniques.

Vulnérable pseudo
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
  // Untrusted input flows directly into the sensitive sink.
  return executeUnsafe(input);
}
Exemple de code sécurisé

Secure pseudo

Sécurisé pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
  const safe = validateAndEscape(input);
  return executeWithGuards(safe);
}
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Liste de contrôle de prévention

How to prevent CWE-1315

  • Architecture and Design For responder devices, the register bit in the fabric end-point that enables the bus controlling capability must be set to 0 by default. This bit should not be set during secure-boot flows. Also, writes to this register must be access-protected to prevent malicious modifications to obtain bus-controlling capability.
  • Implementation For responder devices, the register bit in the fabric end-point that enables the bus controlling capability must be set to 0 by default. This bit should not be set during secure-boot flows. Also, writes to this register must be access-protected to prevent malicious modifications to obtain bus-controlling capability.
  • System Configuration For responder devices, the register bit in the fabric end-point that enables the bus controlling capability must be set to 0 by default. This bit should not be set during secure-boot flows. Also, writes to this register must be access-protected to prevent malicious modifications to obtain bus-controlling capability.
Signaux de détection

How to detect CWE-1315

SAST High

Exécuter une analyse statique (SAST) sur le code source à la recherche du motif non sécurisé dans le flux de données.

DAST Moderate

Exécuter des tests de sécurité applicative dynamique (DAST) contre le point de terminaison en ligne.

Runtime Moderate

Surveiller les journaux runtime pour détecter des traces d'exception inhabituelles, des entrées malformées ou des tentatives de contournement d'autorisation.

Code review Moderate

Revue de code : signaler tout nouveau code qui traite les entrées de cette surface sans utiliser les helpers du framework validés.

Correction automatique Plexicus

Plexicus détecte automatiquement CWE-1315 et ouvre une PR de correction en moins de 60 secondes.

Codex Remedium analyse chaque commit, identifie cette faiblesse précise et livre une pull request prête à être relue avec le correctif. Pas de tickets. Pas de transferts.

Questions fréquentes

Frequently asked questions

Qu'est-ce que CWE-1315 ?

This vulnerability occurs when a hardware fabric endpoint is incorrectly configured to grant bus controller privileges to a device that should only respond to requests. This allows an unauthorized device to initiate and control data transactions across the system bus.

Quelle est la gravité de CWE-1315 ?

MITRE n'a pas publié de note de probabilité d'exploitation pour cette faiblesse. Traitez-la comme un impact moyen jusqu'à ce que votre modèle de menace prouve le contraire.

Quels langages ou plateformes sont affectés par CWE-1315 ?

MITRE lists the following affected platforms: Not OS-Specific, Not Architecture-Specific, Not Technology-Specific.

Comment puis-je prévenir CWE-1315 ?

For responder devices, the register bit in the fabric end-point that enables the bus controlling capability must be set to 0 by default. This bit should not be set during secure-boot flows. Also, writes to this register must be access-protected to prevent malicious modifications to obtain bus-controlling capability. For responder devices, the register bit in the fabric end-point that enables the bus controlling capability must be set to 0 by default. This bit should not be set during…

Comment Plexicus détecte et corrige CWE-1315 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-1315 à chaque commit. Lorsqu'une correspondance est trouvée, notre agent Codex Remedium ouvre une PR de correction avec le code corrigé, les tests et un résumé d'une ligne pour le relecteur.

Où puis-je en savoir plus sur CWE-1315 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/1315.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Faiblesses associées

Weaknesses related to CWE-1315

CWE-284 Parent

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CWE-1191 Frère

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CWE-1220 Frère

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CWE-1224 Frère

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CWE-1231 Frère

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CWE-1233 Frère

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CWE-1252 Frère

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CWE-1257 Frère

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CWE-1259 Frère

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