Horizon Alert
Summary of the vulnerability and why it matters
This vulnerability allows unauthenticated users to submit malicious code through a form field, potentially exposing sensitive system information or enabling remote code execution. The issue arises from insufficient sanitization of user input before it is rendered as a template.
- Unsecured form input can run unauthorized code.
- It impacts server configuration and application source.
- Confirm relevance and assess potential exposure.
Attack Path
How an attacker could exploit the issue
An unauthenticated attacker can exploit this vulnerability by submitting crafted input through a specific form field designed to capture the sender's name. If this field is configured to use a common default setting, the attacker can inject malicious Fluid template syntax. This allows them to execute arbitrary commands, potentially leading to the exposure of sensitive server information and application code, and possibly remote code execution.
- No authentication or user interaction needed.
- Submit malicious Fluid syntax in sender name field.
- Expose server details and execute code.
Live Threat
Current exploitation, exposure, and threat context
An anonymous user can exploit this vulnerability by submitting crafted input into a specific form field. This can lead to the disclosure of sensitive server information, application source code, and potentially allow for arbitrary code execution. This is possible when a form field is configured to capture the sender's name and is vulnerable to template injection.
- Server configuration and application source code.
- Malicious input in a form field.
- Arbitrary code execution and data disclosure.
Operational Fix
Recommended remediation, mitigation, and detection steps
The vulnerability affects web forms that are configured to use a specific sender name field, allowing unauthenticated users to inject and execute arbitrary Fluid ViewHelpers. This could lead to the disclosure of sensitive server information or even remote code execution. Teams responsible for the application, infrastructure, and security should collaborate to address this actively exploited issue. The first practical step is to identify all instances of the affected form field, assess their exposure and business criticality, and then coordinate remediation efforts.
- Application owners should own this issue.
- Verify all sender name form fields.
- Plan for code updates or secure configurations.
