Common Weakness Enumeration

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CWE-565: Reliance on Cookies without Validation and Integrity Checking

Weakness ID: 565
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The application relies on the existence or values of cookies when performing security-critical operations, but it does not properly ensure that the setting is valid for the associated user.
+ Extended Description
Attackers can easily modify cookies, within the browser or by implementing the client-side code outside of the browser. Reliance on cookies without detailed validation and integrity checking can allow attackers to bypass authentication, conduct injection attacks such as SQL injection and cross-site scripting, or otherwise modify inputs in unexpected ways.
+ 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)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
MemberOfCategoryCategory1020Verify Message Integrity
+ Relevant to the view "Development Concepts" (CWE-699)
+ 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 software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

Architecture and DesignOMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
+ 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.

Access Control

Technical Impact: Gain Privileges or Assume Identity

It is dangerous to use cookies to set a user's privileges. The cookie can be manipulated to escalate an attacker's privileges to an administrative level.
+ Demonstrative Examples

Example 1

The following code excerpt reads a value from a browser cookie to determine the role of the user.

(bad code)
Example Language: Java 
Cookie[] cookies = request.getCookies();
for (int i =0; i< cookies.length; i++) {
Cookie c = cookies[i];
if (c.getName().equals("role")) {
userRole = c.getValue();



It is easy for an attacker to modify the "role" value found in the locally stored cookie, allowing privilege escalation.

+ Potential Mitigations

Phase: Architecture and Design

Avoid using cookie data for a security-related decision.

Phase: Implementation

Perform thorough input validation (i.e.: server side validation) on the cookie data if you're going to use it for a security related decision.

Phase: Architecture and Design

Add integrity checks to detect tampering.

Phase: Architecture and Design

Protect critical cookies from replay attacks, since cross-site scripting or other attacks may allow attackers to steal a strongly-encrypted cookie that also passes integrity checks. This mitigation applies to cookies that should only be valid during a single transaction or session. By enforcing timeouts, you may limit the scope of an attack. As part of your integrity check, use an unpredictable, server-side value that is not exposed to the client.
+ 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.
+ Notes


This problem can be primary to many types of weaknesses in web applications. A developer may perform proper validation against URL parameters while assuming that attackers cannot modify cookies. As a result, the program might skip basic input validation to enable cross-site scripting, SQL injection, price tampering, and other attacks..
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
Software Fault PatternsSFP29Faulty endpoint authentication
+ Content History
Submission DateSubmitterOrganization
Anonymous Tool Vendor (under NDA)
Modification DateModifierOrganization
2008-07-01Sean EidemillerCigital
added/updated demonstrative examples
2008-07-01Eric DalciCigital
updated Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes, Taxonomy_Mappings
2009-01-12CWE Content TeamMITRE
updated Common_Consequences, Description, Other_Notes, Potential_Mitigations, Relationships
2009-07-16CWE Content TeamMITRE
Clarified name and description; broadened the definition to include any security-critical operation, not just security decisions, to allow for relationships with injection weaknesses.
2009-07-27CWE Content TeamMITRE
updated Description, Name, Potential_Mitigations, Relationship_Notes, Relationships, Taxonomy_Mappings
2009-10-29CWE Content TeamMITRE
updated Relationships
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-11-08CWE Content TeamMITRE
updated Modes_of_Introduction, Relationships
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Use of Cookies
2009-07-27Use of Cookies in Security Decision

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Page Last Updated: January 18, 2018