Weakness · High
CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag
What it is
The product uses a cookie to store sensitive information, but the cookie is not marked with the HttpOnly flag.
- Severity (our rating)
- High
- Likelihood of exploit
- Medium
- Introduced during
- Implementation
- Exploited in the wild
- No CVE in CISA's catalog
In more detail
The HttpOnly flag directs compatible browsers to prevent client-side script from accessing cookies. Including the HttpOnly flag in the Set-Cookie HTTP response header helps mitigate the risk associated with Cross-Site Scripting (XSS) where an attacker's script code might attempt to read the contents of a cookie and exfiltrate information obtained. When set, browsers that support the flag will not reveal the contents of the cookie to a third party via client-side script executed via XSS.
What an attacker can do
- Read Application Data (Confidentiality)
- Gain Privileges or Assume Identity (Integrity)
How to prevent it
Implementation
- Leverage the HttpOnly flag when setting a sensitive cookie in a response.
How to find it
- Automated Static Analysis. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.