CWE-565: Reliance on Cookies without Validation and Integrity Checking
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.
How it's found
Reliance on Cookies without Validation and Integrity Checking is typically found by tracing untrusted input from where it enters the system to the point where it is used without the check or neutralization this weakness describes, combining manual code review with dynamic testing.
Consequences
- Modify Application Data, Execute Unauthorized Code or Commands: 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.
- 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.
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.
Where this fits in a TurboPentest engagement
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Frequently asked questions
What is CWE-565?
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.
How do you find Reliance on Cookies without Validation and Integrity Checking?
Reliance on Cookies without Validation and Integrity Checking is typically found by tracing untrusted input from where it enters the system to the point where it is used without the check or neutralization this weakness describes, combining manual code review with dynamic testing.
What is the impact of CWE-565?
Modify Application Data, Execute Unauthorized Code or Commands: 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. 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.
Does TurboPentest test for Reliance on Cookies without Validation and Integrity Checking?
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
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Written and reviewed by
Michel Chamberland - Founder & CEO, IntegSec
CISSP, OSCP, OSCE, CEH, GIAC, CCSK · 20+ years in offensive security
Michel has spent 20+ years on offensive security teams including IBM X-Force Red and Trustwave SpiderLabs, leading penetration tests, red team engagements, and breach response for Fortune 500 customers. He is the founder of IntegSec and the architect of TurboPentest.
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