CWE

ASP.NET Misconfiguration: Missing Custom Error Page

ID: 12		Date: (C)2012-05-14   (M)2022-10-10
Type: weakness		Status: DRAFT
Abstraction Type: Variant

Description

An ASP .NET application must enable custom error pages in order to prevent attackers from mining information from the framework's built-in responses.

Applicable Platforms
Language: .NET

Time Of Introduction

• Implementation
• Operation

Common Consequences

Scope	Technical Impact	Notes
Confidentiality	Read application data	Default error pages gives detailed information about the error that occurred, and should not be used in production environments. Attackers can leverage the additional information provided by a default error page to mount attacks targeted on the framework, database, or other resources used by the application.

Detection Methods
None

Potential Mitigations

Phase	Strategy	Description	Effectiveness	Notes
		Handle exceptions appropriately in source code. The best practice is to use a custom error message. Make sure that the mode attribute is set to "RemoteOnly" in the web.config file as shown in the following example. The mode attribute of the <customErrors> tag in the Web.config file defines whether custom or default error pages are used. It should be configured to use a custom page as follows:
		Do not attempt to process an error or attempt to mask it.
		Verify return values are correct and do not supply sensitive information about the system.
System Configuration		ASP .NET applications should be configured to use custom error pages instead of the framework default page.

Relationships

Related CWE	Type	View	Chain
CWE-12 ChildOf CWE-895	Category	CWE-888

Demonstrative Examples   (Details)

1. An insecure ASP.NET application setting: (Demonstrative Example Id DX-75)

White Box Definitions
None

Black Box Definitions
None

Taxynomy Mappings

Taxynomy	Id	Name	Fit
7 Pernicious Kingdoms		ASP.NET Misconfiguration: Missing Custom Error Handling

References:

1. M. Howard D. LeBlanc J. Viega .19 Deadly Sins of Software Security. McGraw-Hill/Osborne. Published on 2005.
2. OWASP, Fortify Software .ASP.NET Misconfiguration: Missing Custom Error Handling.