1977
Scope Impact Likelihood
to modify the functionality of the shared resource of the
trusted user.
Integrity Quality Degradation
The functionality of the shared resource may be
intentionally degraded.
Detection Methods
Automated Dynamic Analysis
Pre-silicon / post-silicon: Test access to shared systems resources (memory ranges, control
registers, etc.) from untrusted software to verify that the assets are not incorrectly exposed to
untrusted agents. Note that access to shared resources can be dynamically allowed or revoked
based on system flows. Security testing should cover such dynamic shared resource allocation
and access control modification flows.
Effectiveness = High
Potential Mitigations
Phase: Architecture and Design
Strategy = Separation of Privilege
When sharing resources, avoid mixing agents of varying trust levels. Untrusted agents should not
share resources with trusted agents.
Demonstrative Examples
Example 1:
Consider the following SoC design. The Hardware Root of Trust (HRoT) local SRAM is memory
mapped in the core{0-N} address space. The HRoT allows or disallows access to private memory
ranges, thus allowing the sram to function as a mailbox for communication between untrusted and
trusted HRoT partitions.
We assume that the threat is from malicious software in the untrusted domain. We assume this
software has access to the core{0-N} memory map and can be running at any privilege level on
the untrusted cores. The capability of this threat in this example is communication to and from the
mailbox region of SRAM modulated by the hrot_iface. To address this threat, information must not
enter or exit the shared region of SRAM through hrot_iface when in secure or privileged mode.
Observed Examples
Reference Description
CVE-2020-8698 Processor has improper isolation of shared resources allowing for information
disclosure.
https://www.cve.org/CVERecord?id=CVE-2020-8698
CVE-2019-6260 Baseboard Management Controller (BMC) device implements Advanced Highperformance
Bus (AHB) bridges that do not require authentication for arbitrary
read and write access to the BMC's physical address space from the host, and
possibly the network [REF-1138].
https://www.cve.org/CVERecord?id=CVE-2019-6260
MemberOf Relationships
This MemberOf relationships table shows additional CWE Catgeories and Views that reference this
weakness as a member. This information is often useful in understanding where a weakness fits
within the context of external information sources.
CWE Version 4.14
CWE-1190: DMA Device Enabled Too Early in Boot Phase
CWE-1190: DMA Device Enabled Too Early in Boot Phase