Missing an ability to patch ROM code may leave a System or System-on-Chip (SoC) in a vulnerable state.
Extended Description
A System or System-on-Chip (SoC) that implements a boot process utilizing security mechanisms such as Root-of-Trust (RoT) typically starts by executing code from a Read-only-Memory (ROM) component. The code in ROM is immutable, hence any security vulnerabilities discovered in the ROM code can never be fixed for the systems that are already in use.
A common weakness is that the ROM does not have the ability to patch if security vulnerabilities are uncovered after the system gets shipped. This leaves the system in a vulnerable state where an adversary can compromise the SoC.
Relationships
This table 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)
Nature
Type
ID
Name
ChildOf
Base - a weakness
that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.
This table 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 "Hardware Design" (CWE-1194)
Nature
Type
ID
Name
MemberOf
Category - a CWE entry that contains a set of other entries that share a common characteristic.
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.
Phase
Note
Architecture and Design
This issue could be introduced during hardware architecture and design and can be identified later during Testing.
Implementation
This issue could be introduced during implementation and can be identified later during Testing.
Integration
This issue could be introduced during integration and can be identified later during Testing.
Manufacturing
This issue could be introduced during manufacturing and can be identified later during Testing.
Applicable Platforms
This listing shows 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.
This table 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.
Scope
Impact
Likelihood
Other
Technical Impact: Varies by Context; Reduce Maintainability
When the system is unable to be patched, it can be left in a vulnerable state.
High
Demonstrative Examples
Example 1
A System-on-Chip (SOC) implements a Root-of-Trust (RoT) in ROM to boot secure code. However, at times this ROM code might have security vulnerabilities and need to be patched. Since ROM is immutable, it can be impossible to patch.
ROM does not have built-in application-programming interfaces (APIs) to patch if the code is vulnerable. Implement mechanisms to patch the vulnerable ROM code.
Potential Mitigations
Phases: Architecture and Design; Implementation
Secure patch support to allow ROM code to be patched on the next boot.
Effectiveness: Moderate
Note:
Some parts of the hardware initialization or signature verification done to authenticate patches will always be "not patchable."
Phases: Architecture and Design; Implementation
Support patches that can be programmed in-field or during manufacturing through hardware fuses. This feature can be used for limited patching of devices after shipping, or for the next batch of silicon devices manufactured, without changing the full device ROM.
Effectiveness: Moderate
Note:
Patches that use hardware fuses will have limitations in terms of size and the number of patches that can be supported. Note that some parts of the hardware initialization or signature verification done to authenticate patches will always be "not patchable."
References
[REF-1121] Moritz Lipp, Michael Schwarz, Daniel Gruss, Thomas Prescher, Werner Haas, Anders Fogh, Jann Horn, Stegfan Mangard, Paul Kocher, Daniel Genkin, Yuval Yarom
and Mike Hamberg. "Meltdown: Reading Kernel Memory from User Space". 2018-01-03.
<https://meltdownattack.com/meltdown.pdf>.
[REF-1122] Moritz Lipp, Michael Schwarz, Daniel Gruss, Thomas Prescher, Werner Haas, Anders Fogh, Jann Horn, Stegfan Mangard, Paul Kocher, Daniel Genkin, Yuval Yarom
and Mike Hamberg. "Spectre Attacks: Exploiting Speculative Execution". 2018-01-03.
<https://spectreattack.com/spectre.pdf>.
[REF-1124] Qian Ge, Yuval Yarom, David Cock
and Gernot Heiser. "A Survey of Microarchitectural Timing Attacks and Countermeasures on Contemporary Hardware". 2016-10-24.
<https://eprint.iacr.org/2016/613.pdf>.
Description
This table 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.
