COMMON WEAKNESS ENUMERATIONIncomplete

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.

Abstraction

Variant

Structure

Simple

Likelihood of Exploit

High

Understand the problem

What is the problem?

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.

Extended description

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.

Root cause

How and when does the problem arise?

Lifecycle phase

Implementation

Risk

What does successful exploitation lead to?

Execute Unauthorized Code or Commands

Affected security scopes: Integrity, Confidentiality, Availability

Run arbitrary code.
Read Application Data

Affected security scopes: Confidentiality

Attackers may be able to obtain sensitive information.

Defence

How is it prevented and fixed?

Architecture and Design

Architecture and design approach

Detail
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

Architecture and design approach

Detail
Disable script execution functionality in the clients' browser.