CWE-352: Cross-Site Request Forgery (CSRF)

Abstraction	Structure	Status
None	Composite	Stable

Description

The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.

Alternate Terms

Session Riding:
Cross Site Reference Forgery:
XSRF:
CSRF:

Nature	ID	View ID	Name
ChildOf	CWE-345	1000	Insufficient Verification of Data Authenticity
ChildOf	CWE-345	1003	Insufficient Verification of Data Authenticity
Requires	CWE-346	1000	Origin Validation Error
Requires	CWE-441	1000	Unintended Proxy or Intermediary (‘Confused Deputy’)
Requires	CWE-642	1000	External Control of Critical State Data
Requires	CWE-613	1000	Insufficient Session Expiration

Modes of Introduction

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

Applicable Platforms

Languages

Class: Not Language-Specific

Technologies

Class: Web Based Class: None

Likelihood Of Exploit

Medium

Common Consequences

Scope	Impact	Note
Confidentiality, Integrity, Availability, Non-Repudiation, Access Control	Gain Privileges or Assume Identity, Bypass Protection Mechanism, Read Application Data, Modify Application Data, DoS: Crash, Exit, or Restart	The consequences will vary depending on the nature of the functionality that is vulnerable to CSRF. An attacker could trick a client into making an unintentional request to the web server via a URL, image load, XMLHttpRequest, etc., which would then be treated as an authentic request from the client - effectively performing any operations as the victim, leading to an exposure of data, unintended code execution, etc. If the victim is an administrator or privileged user, the consequences may include obtaining complete control over the web application - deleting or stealing data, uninstalling the product, or using it to launch other attacks against all of the product’s users. Because the attacker has the identity of the victim, the scope of CSRF is limited only by the victim’s privileges.

Detection Methods

Manual Analysis

This weakness can be detected using tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session.

Specifically, manual analysis can be useful for finding this weakness, and for minimizing false positives assuming an understanding of business logic. However, it might not achieve desired code coverage within limited time constraints. For black-box analysis, if credentials are not known for privileged accounts, then the most security-critical portions of the application may not receive sufficient attention.

Consider using OWASP CSRFTester to identify potential issues and aid in manual analysis.

Effectiveness: High

Note: These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Automated Static Analysis

CSRF is currently difficult to detect reliably using automated techniques. This is because each application has its own implicit security policy that dictates which requests can be influenced by an outsider and automatically performed on behalf of a user, versus which requests require strong confidence that the user intends to make the request. For example, a keyword search of the public portion of a web site is typically expected to be encoded within a link that can be launched automatically when the user clicks on the link.

Effectiveness: Limited