Horizon Alert
Summary of the vulnerability and why it matters
A vulnerability in the Python StateMachine library allows for remote code execution when processing specially crafted SCXML documents. This could enable an attacker to run arbitrary code on systems using affected versions of the library, with the potential impact dependent on how the library is integrated into an application.
- Code execution via malicious document input.
- Library vulnerability impacts application security.
- Confirm relevance and assess potential exposure.
Attack Path
How an attacker could exploit the issue
An attacker can trigger this vulnerability by providing a specially crafted SCXML document to an application that uses the vulnerable Python StateMachine library. This document would contain malicious code within `<data expr="...">` attributes, which the application then processes. Because the library evaluates these expressions unsafely using Python's `eval()` function without proper sandboxing, the attacker can execute arbitrary code on the server running the application.
- No authentication or user interaction required.
- Supplying a malicious SCXML document triggers the vulnerability.
- Risk of arbitrary code execution.
Live Threat
Current exploitation, exposure, and threat context
The Python StateMachine library could allow attackers to execute arbitrary code within the hosting process when processing specially crafted SCXML documents. This occurs because the library passes expression strings to Python's `eval()` function without adequate security measures, enabling malicious code execution under specific conditions.
- Hosting process memory and code execution.
- Malicious SCXML documents processed by the library.
- Arbitrary code execution in the application context.
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability in Python StateMachine affects applications processing untrusted SCXML data. Ownership likely lies with the application development team that integrated the library, with support from platform or infrastructure teams for deployment. The initial action is to inventory all deployments, assess exposure, and identify the business criticality of each instance.
- Application owners should manage the issue.
- Verify SCXML processing reachability and criticality.
- Plan remediation based on assessed risk.
