CAPEC-104: Cross Zone Scripting
Description
An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security.
- Likelihood of attack
- Medium
- Typical severity
- High
- Abstraction
- StandardA specific methodology or technique used in an attack.
Mechanism of attack: Subvert Access Control
Prerequisites
- The target must be using a zone-aware browser.
Skills required
- MediumAbility to craft malicious scripts or find them elsewhere and ability to identify functionality that is running web controls in the local zone and to find an injection vector into that functionality
Consequences
- Integrity
Modify Data
- Confidentiality
Read Data
- ConfidentialityAccess ControlAuthorization
Gain Privileges
- ConfidentialityIntegrityAvailability
Execute Unauthorized Commands
Run Arbitrary Code
Mitigations
- Disable script execution.
- Ensure that sufficient input validation is performed for any potentially untrusted data before it is used in any privileged context or zone
- Limit the flow of untrusted data into the privileged areas of the system that run in the higher trust zone
- Limit the sites that are being added to the local machine zone and restrict the privileges of the code running in that zone to the bare minimum
- Ensure proper HTML output encoding before writing user supplied data to the page