CWE - CWE-827: Improper Control of Document Type Definition (4.4)

Weakness ID: 827

Abstraction: Variant
Structure: Simple

Status: Incomplete

Presentation Filter:

Description

The software does not restrict a reference to a Document Type Definition (DTD) to the intended control sphere. This might allow attackers to reference arbitrary DTDs, possibly causing the software to expose files, consume excessive system resources, or execute arbitrary http requests on behalf of the attacker.

Extended Description

As DTDs are processed, they might try to read or include files on the machine performing the parsing. If an attacker is able to control the DTD, then the attacker might be able to specify sensitive resources or requests or provide malicious content.

For example, the SOAP specification prohibits SOAP messages from containing DTDs.

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)

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.	829	Inclusion of Functionality from Untrusted Control Sphere
ChildOf	Class - 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.	706	Use of Incorrectly-Resolved Name or Reference
CanPrecede	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.	776	Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1011	Authorize Actors

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.

Phase	Note
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.

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.

Languages

XML (Undetermined Prevalence)

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.

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Files or Directories If the attacker is able to include a crafted DTD and a default entity resolver is enabled, the attacker may be able to access arbitrary files on the system.
Availability	Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory) The DTD may cause the parser to consume excessive CPU cycles or memory using techniques such as nested or recursive entity references (CWE-776).
Integrity Confidentiality Availability Access Control	Technical Impact: Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity The DTD may include arbitrary HTTP requests that the server may execute. This could lead to other attacks leveraging the server's trust relationship with other entities.

Observed Examples

Reference	Description
CVE-2010-2076	Product does not properly reject DTDs in SOAP messages, which allows remote attackers to read arbitrary files, send HTTP requests to intranet servers, or cause a denial of service.

References

[REF-773] Daniel Kulp. "Apache CXF Security Advisory (CVE-2010-2076)". 2010-06-16. <http://svn.apache.org/repos/asf/cxf/trunk/security/CVE-2010-2076.pdf>.

Content History

Submissions
Submission Date	Submitter	Organization
2010-10-25	CWE Content Team	MITRE
2010-10-25
Modifications
Modification Date	Modifier	Organization
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences
2013-02-21	CWE Content Team	MITRE
2013-02-21	updated Applicable_Platforms
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Modes_of_Introduction, Relationships
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Type
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Relationships


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Common Weakness Enumeration

CWE-827: Improper Control of Document Type Definition