Home > CAPEC List > CAPEC-271: Schema Poisoning (Version 3.0)  

CAPEC-271: Schema Poisoning

Attack Pattern ID: 271
Abstraction: Standard
Status: Draft
Presentation Filter:
+ Description
An adversary corrupts or modifies the content of a schema for the purpose of undermining the security of the target. Schemas provide the structure and content definitions for resources used by an application. By replacing or modifying a schema, the adversary can affect how the application handles or interprets a resource, often leading to possible denial of service, entering into an unexpected state, or recording incomplete data.
+ Likelihood Of Attack

Low

+ Typical Severity

High

+ Relationships

The table(s) below shows the other attack patterns and high level categories that are related to this attack pattern. 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 CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.

+ Relevant to the view "Mechanisms of Attack" (CAPEC-1000)
NatureTypeIDName
ChildOfMeta Attack PatternMeta Attack Pattern - A meta level attack pattern in CAPEC is a decidedly abstract characterization of a specific methodology or technique used in an attack. A meta attack pattern is often void of a specific technology or implementation and is meant to provide an understanding of a high level approach. A meta level attack pattern is a generalization of related group of standard level attack patterns. Meta level attack patterns are particularly useful for architecture and design level threat modeling exercises.176Configuration/Environment Manipulation
ParentOfDetailed Attack PatternDetailed Attack Pattern - A detailed level attack pattern in CAPEC provides a low level of detail, typically leveraging a specific technique and targeting a specific technology, and expresses a complete execution flow. Detailed attack patterns are more specific than meta attack patterns and standard attack patterns and often require a specific protection mechanism to mitigate actual attacks. A detailed level attack pattern often will leverage a number of different standard level attack patterns chained together to accomplish a goal.146XML Schema Poisoning
+ Prerequisites
Some level of access to modify the target schema.
The schema used by the target application must be improperly secured against unauthorized modification and manipulation.
+ Resources Required
Access to the schema and the knowledge and ability modify it. Ability to replace or redirect access to the modified schema.
+ Consequences

The table below specifies different individual consequences associated with the attack pattern. The Scope identifies the security property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in their attack. 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 pattern will be used to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Availability
Unreliable Execution
Resource Consumption
Integrity
Modify Data
Confidentiality
Read Data
+ Mitigations
Design: Protect the schema against unauthorized modification.
Implementation: For applications that use a known schema, use a local copy or a known good repository instead of the schema reference supplied in the schema document.
Implementation: For applications that leverage remote schemas, use the HTTPS protocol to prevent modification of traffic in transit and to avoid unauthorized modification.
+ Example Instances

In a JSON Schema Poisoning Attack, an adervary modifies the JSON schema to cause a Denial of Service (DOS) or to submit malicious input:

{ "title": "Contact", "type": "object", "properties": { "Name": { "type": "string" }, "Phone": { "type": "string" }, "Email": { "type": "string" }, "Address": { "type": "string" } }, "required": ["Name", "Phone", "Email", "Address"] }

If the 'name' attribute is required in all submitted documents and this field is removed by the adversary, the application may enter an unexpected state or record incomplete data. Additionally, if this data is needed to perform additional functions, a Denial of Service (DOS) may occur.

In a Database Schema Poisoning Attack, an adversary alters the database schema being used to modify the database in some way. This can result in loss of data, DOS, or malicious input being submitted. Assuming there is a column named "name", an adversary could make the following schema change:

ALTER TABLE Contacts MODIFY Name VARCHAR(65353);

The "Name" field of the "Conteacts" table now allows the storing of names up to 65353 characters in length. This could allow the adversary to store excess data within the database to consume system resource or to execute a DOS.

+ Content History
Submissions
Submission DateSubmitterOrganization
2014-06-23CAPEC Content TeamThe MITRE Corporation
Modifications
Modification DateModifierOrganization
2017-01-09CAPEC Content TeamThe MITRE Corporation
Updated Description, Description Summary, Related_Attack_Patterns
2018-07-31CAPEC Content TeamThe MITRE Corporation
Updated Attack_Motivation-Consequences, Attack_Prerequisites, Description Summary, Examples-Instances, Related_Weaknesses, Resources_Required, Solutions_and_Mitigations, Typical_Likelihood_of_Exploit, Typical_Severity

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Page Last Updated or Reviewed: July 31, 2018