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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.

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.

Modes of Introduction:

– Architecture and Design

 

 

Related Weaknesses

CWE-642
CWE-669
CWE-602

 

Consequences

Access Control: 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.

 

Potential Mitigations

Phase: Architecture and Design

Description: 

Avoid using cookie data for a security-related decision.

Phase: Implementation

Description: 

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

Description: 

Add integrity checks to detect tampering.

Phase: Architecture and Design

Description: 

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.

CVE References