Détail du CWE-1316

The address map of the on-chip fabric has protected and unprotected regions overlapping, allowing an attacker to bypass access control to the overlapping portion of the protected region.

Various ranges can be defined in the system-address map, either in the memory or in Memory-Mapped-IO (MMIO) space. These ranges are usually defined using special range registers that contain information, such as base address and size. Address decoding is the process of determining for which range the incoming transaction is destined. To ensure isolation, ranges containing secret data are access-control protected.

Occasionally, these ranges could overlap. The overlap could either be intentional (e.g. due to a limited number of range registers or limited choice in choosing size of the range) or unintentional (e.g. introduced by errors). Some hardware designs allow dynamic remapping of address ranges assigned to peripheral MMIO ranges. In such designs, intentional address overlaps can be created through misconfiguration by malicious software. When protected and unprotected ranges overlap, an attacker could send a transaction and potentially compromise the protections in place, violating the principle of least privilege.

Modes d'introduction

Architecture and Design
Implementation

Plateformes applicables

Langue

Class: Not Language-Specific (Undetermined)

Systèmes d’exploitation

Class: Not OS-Specific (Undetermined)

Architectures

Class: Not Architecture-Specific (Undetermined)

Technologies

Name: Bus/Interface Hardware (Undetermined)
Class: Not Technology-Specific (Undetermined)

Conséquences courantes

Exemples observés

Mesures d’atténuation potentielles

Phases : Architecture and Design
When architecting the address map of the chip, ensure that protected and unprotected ranges are isolated and do not overlap. When designing, ensure that ranges hardcoded in Register-Transfer Level (RTL) do not overlap.
Phases : Implementation
Ranges configured by firmware should not overlap. If overlaps are mandatory because of constraints such as a limited number of registers, then ensure that no assets are present in the overlapped portion.
Phases : Testing
Validate mitigation actions with robust testing.

Méthodes de détection

Automated Dynamic Analysis

Review address map in specification to see if there are any overlapping ranges.
Efficacité : High

Manual Static Analysis

Negative testing of access control on overlapped ranges.
Efficacité : High

Notes de cartographie des vulnérabilités

Justification : 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.
Commentaire : 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.

Modèles d'attaque associés

NotesNotes

As of CWE 4.6, CWE-1260 and CWE-1316 are siblings under view 1000, but CWE-1260 might be a parent of CWE-1316. More analysis is warranted.

Références

REF-1137

BARing the System - New vulnerabilities in Coreboot & UEFI-based Systems
Yuriy Bulygin, Oleksandr Bazhaniuk, Andrew Furtak, John Loucaides, Mikhail Gorobets.
https://www.c7zero.info/stuff/REConBrussels2017_BARing_the_system.pdf

Soumission

Modifications