Common Weakness Enumeration

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CWE-1037: Processor Optimization Removal or Modification of Security-critical Code

Weakness ID: 1037
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The developer builds a security-critical protection mechanism into the software, but the processor optimizes the execution of the program such that the mechanism is removed or modified.
+ Relationships

The table(s) below 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)
ChildOfClassClass - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.1038Insecure Automated Optimizations
PeerOfBaseBase - 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.1264Hardware Logic with Insecure De-Synchronization between Control and Data Channels
+ Relevant to the view "Software Development" (CWE-699)
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.438Behavioral Problems
+ Modes Of Introduction

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.

Architecture and DesignOptimizations built into the design of the processor can have unintended consequences during the execution of an application.
+ Applicable Platforms
The listings below show 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.


Class: Language-Independent (Rarely Prevalent)

+ Common Consequences

The table below 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.


Technical Impact: Bypass Protection Mechanism

A successful exploitation of this weakness will change the order of an application's execution and will likely be used to bypass specific protection mechanisms. This bypass can be exploited further to potentially read data that should otherwise be unaccessible.
+ Likelihood Of Exploit
+ Observed Examples
Intel, ARM, and AMD processor optimizations related to speculative execution and branch prediction cause access control checks to be bypassed when placing data into the cache. Often known as "Spectre".
Intel, ARM, and AMD processor optimizations related to speculative execution and branch prediction cause access control checks to be bypassed when placing data into the cache. Often known as "Spectre".
Intel processor optimizations related to speculative execution cause access control checks to be bypassed when placing data into the cache. Often known as "Meltdown".
+ Weakness Ordinalities
This weakness does not depend on other weaknesses and is the result of choices made by the processor in executing the specified application. (where the weakness is a quality issue that might indirectly make it easier to introduce security-relevant weaknesses or make them more difficult to detect)
+ Detection Methods

White Box

In theory this weakness can be detected through the use of white box testing techniques where specifically crafted test cases are used in conjunction with debuggers to verify the order of statements being executed.

Effectiveness: Opportunistic

Note: Although the mentioned detection method is theoretically possible, the use of speculative execution is a preferred way of increasing processor performance. The reality is that a large number of statements are executed out of order, and determining if any of them break an access control property would be extremely opportunistic.
+ References
[REF-11] Paul Kocher, Daniel Genkin, Daniel Gruss, Werner Haas, Mike Hamburg, Moritz Lipp, Stefan Mangard, Thomas Prescher, Michael Schwarz and Yuval Yarom. "Spectre Attacks: Exploiting Speculative Execution". 2018-01-03. <>.
[REF-12] Moritz Lipp, Michael Schwarz, Daniel Gruss, Thomas Prescher, Werner Haas, Stefan Mangard, Paul Kocher, Daniel Genkin, Yuval Yarom and Mike Hamburg. "Meltdown". 2018-01-03. <>.
+ Content History
+ Submissions
Submission DateSubmitterOrganization
2018-03-07CWE Content TeamMITRE
+ Modifications
Modification DateModifierOrganization
2020-02-24CWE Content TeamMITRE
updated Relationships
2020-06-25CWE Content TeamMITRE
updated Relationships
2021-03-15CWE Content TeamMITRE
updated Related_Attack_Patterns
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Page Last Updated: March 15, 2021