CWE-644: Improper Neutralization of HTTP Headers for Scripting Syntax
The product does not neutralize or incorrectly neutralizes web scripting syntax in HTTP headers that can be used by web browser components that can process raw headers, such as Flash.
How it's found
Improper Neutralization of HTTP Headers for Scripting Syntax is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
An attacker may be able to conduct cross-site scripting and other attacks against users who have these components enabled. If a product does not neutralize user controlled data being placed in the header of an HTTP response coming from the server, the header may contain a script that will get executed in the client's browser context, potentially resulting in a cross site scripting vulnerability or possibly an HTTP response splitting attack. It is important to carefully control data that is being placed both in HTTP response header and in the HTTP response body to ensure that no scripting syntax is present, taking various encodings into account.
Consequences
- Execute Unauthorized Code or Commands: Run arbitrary code.
- Read Application Data: Attackers may be able to obtain sensitive information.
Mitigations
- Architecture and Design: Perform output validation in order to filter/escape/encode unsafe data that is being passed from the server in an HTTP response header.
- Architecture and Design: Disable script execution functionality in the clients' browser.
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-644?
The product does not neutralize or incorrectly neutralizes web scripting syntax in HTTP headers that can be used by web browser components that can process raw headers, such as Flash.
How do you find Improper Neutralization of HTTP Headers for Scripting Syntax?
Improper Neutralization of HTTP Headers for Scripting Syntax is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
What is the impact of CWE-644?
Execute Unauthorized Code or Commands: Run arbitrary code. Read Application Data: Attackers may be able to obtain sensitive information.
Does TurboPentest test for Improper Neutralization of HTTP Headers for Scripting Syntax?
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Related CWEs
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.
Find these issues before an attacker does
TurboPentest runs an agentic AI pentest against your target and reports findings with proof, from $99 per target.
Start a pentest