CWE-942 Detail

CWE-942

Permissive Cross-domain Security Policy with Untrusted Domains
Incomplete
2014-06-23
00h00 +00:00
2025-12-11
00h00 +00:00
CWE Mitre.org
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Name: Permissive Cross-domain Security Policy with Untrusted Domains

The product uses a web-client protection mechanism such as a Content Security Policy (CSP) or cross-domain policy file, but the policy includes untrusted domains with which the web client is allowed to communicate.

General Informations

Background Details

Modes Of Introduction

Implementation
Architecture and Design : COMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.

Applicable Platforms

Language

Class: Not Language-Specific (Undetermined)

Technologies

Class: Web Based (Undetermined)
Name: Web Server (Undetermined)

Common Consequences

Scope Impact Likelihood
Confidentiality
Integrity
Availability
Access Control		Execute Unauthorized Code or Commands, Bypass Protection Mechanism, Read Application Data, Varies by Context

Note: With an overly permissive policy file, an attacker may be able to bypass the web browser's same-origin policy and conduct many of the same attacks seen in Cross-Site Scripting (CWE-79). An attacker can exploit the weakness to transfer private information from the victim's machine to the attacker, manipulate or steal cookies that may include session information, create malicious requests to a web site on behalf of the victim, or execute malicious code on the end user systems. Other damaging attacks include the disclosure of end user files, installation of Trojan horse programs, redirecting the user to some other page or site, running ActiveX controls (under Microsoft Internet Explorer) from sites that a user perceives as trustworthy, and modifying presentation of content.

Observed Examples

References Description

CVE-2012-2292

Product has a Silverlight cross-domain policy that does not restrict access to another application, which allows remote attackers to bypass the Same Origin Policy.

CVE-2014-2049

The default Flash Cross Domain policies in a product allows remote attackers to access user files.

CVE-2007-6243

Chain: Adobe Flash Player does not sufficiently restrict the interpretation and usage of cross-domain policy files, which makes it easier for remote attackers to conduct cross-domain and cross-site scripting (XSS) attacks.

CVE-2008-4822

Chain: Adobe Flash Player and earlier does not properly interpret policy files, which allows remote attackers to bypass a non-root domain policy.

CVE-2010-3636

Chain: Adobe Flash Player does not properly handle unspecified encodings during the parsing of a cross-domain policy file, which allows remote web servers to bypass intended access restrictions via unknown vectors.

Potential Mitigations

Phases : Architecture and Design // Operation
Define a restrictive Content Security Policy [REF-1486] or cross-domain policy file.
Phases : Architecture and Design // Operation
Avoid using wildcards in the CSP / cross-domain policy file. Any domain matching the wildcard expression will be implicitly trusted, and can perform two-way interaction with the target server.
Phases : Architecture and Design // Operation
For Flash, modify crossdomain.xml to use meta-policy options such as 'master-only' or 'none' to reduce the possibility of an attacker planting extraneous cross-domain policy files on a server.

Detection Methods

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Effectiveness : High

Vulnerability Mapping Notes

Justification : 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.
Comment : 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-1486

Content Security Policy Cheat Sheet
OWASP.
https://cheatsheetseries.owasp.org/cheatsheets/Content_Security_Policy_Cheat_Sheet.html

REF-943

Setting a crossdomain.xml file for HTTP streaming
Apurva Udaykumar.
https://web.archive.org/web/20121124184922/http://www.adobe.com/devnet/adobe-media-server/articles/cross-domain-xml-for-streaming.html

REF-944

Cross-domain policy for Flash movies
Adobe.
http://kb2.adobe.com/cps/142/tn_14213.html

REF-945

HTTP Communication and Security with Silverlight
Microsoft Corporation.
https://learn.microsoft.com/en-us/previous-versions/windows/silverlight/dotnet-windows-silverlight/cc838250(v=vs.95)?redirectedfrom=MSDN

REF-946

Network Security Access Restrictions in Silverlight
Microsoft Corporation.
https://learn.microsoft.com/en-us/previous-versions/windows/silverlight/dotnet-windows-silverlight/cc645032(v=vs.95)

REF-947

Analyzing the Crossdomain Policies of Flash Applications
Dongseok Jang, Aishwarya Venkataraman, G. Michael Sawka, Hovav Shacham.
http://cseweb.ucsd.edu/~hovav/dist/crossdomain.pdf

Submission

Name Organization Date Date release Version
CWE Content Team MITRE 2014-06-05 +00:00 2014-06-23 +00:00 2.7

Modifications

Name Organization Date Comment
CWE Content Team MITRE 2017-11-08 +00:00 updated Modes_of_Introduction, References, Relationships
CWE Content Team MITRE 2019-06-20 +00:00 updated Relationships
CWE Content Team MITRE 2020-02-24 +00:00 updated Applicable_Platforms, Relationships
CWE Content Team MITRE 2020-06-25 +00:00 updated Description, Name
CWE Content Team MITRE 2021-10-28 +00:00 updated Relationships
CWE Content Team MITRE 2023-01-31 +00:00 updated Description, Relationships
CWE Content Team MITRE 2023-04-27 +00:00 updated Detection_Factors, References, Relationships
CWE Content Team MITRE 2023-06-29 +00:00 updated Mapping_Notes, Relationships
CWE Content Team MITRE 2024-02-29 +00:00 updated Demonstrative_Examples
CWE Content Team MITRE 2025-09-09 +00:00 updated Background_Details, Common_Consequences, Description, Name, Potential_Mitigations, References
CWE Content Team MITRE 2025-12-11 +00:00 updated Applicable_Platforms, Relationships, Weakness_Ordinalities
The information presented on CVE Find originates from several carefully selected reference sources. CVE data is provided by MITRE Corporation and the National Vulnerability Database (NVD). The Known Exploited Vulnerabilities (KEV) catalog is sourced from the Cybersecurity and Infrastructure Security Agency (CISA), while EPSS scores come from FIRST.org. Additionally, data regarding software weaknesses (CWE) and common attack patterns (CAPEC) is maintained by MITRE Corporation, and information on hardware and software configurations (CPE) is provided by the NVD.