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

MITRE CWE weakness

Description

The product 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.

Common consequences

• Confidentiality, Integrity, Availability: Modify Application Data, Execute Unauthorized Code or Commands
• Access Control: Gain Privileges or Assume Identity

Mitigations

Architecture and Design — Avoid using cookie data for a security-related decision.

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.

Architecture and Design — Add integrity checks to detect tampering.

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.

References

• CWE page: https://cwe.mitre.org/data/definitions/565.html
• CWE list: https://cwe.mitre.org/data/index.html