Calc Tool

Security checks across malware telemetry and agentic risk

Overview

This calculator skill can run arbitrary Python code through a crafted calculation, which is much broader than users would expect.

Review before installing. This does not appear intentionally malicious, but do not use it with copied, generated, or untrusted expressions until eval() is replaced with a constrained math parser or AST allowlist.

SkillSpector

By NVIDIA
Vulnerability Patterns
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • Behavioral ASTexec() Call, eval() Call, Dynamic Import
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Findings (3)

eval() call detected

High
Category
Dangerous Code Execution
Content
expr = expr.replace('^', '**')
    
    try:
        result = eval(expr)
        return result
    except Exception as e:
        raise ValueError(f"Invalid expression: {e}")
Confidence
99% confidence
Finding
result = eval(expr)

Context-Inappropriate Capability

High
Confidence
99% confidence
Finding
Although the skill is described as a calculator, it evaluates arbitrary Python expressions after superficial string replacement. This means the effective attack surface is Python code execution, not mathematical calculation, so any user supplying the expression can abuse the tool beyond its stated purpose.

Description-Behavior Mismatch

High
Confidence
97% confidence
Finding
There is a security-significant mismatch between the skill's declared purpose and its real behavior: a 'math calculator' that actually executes unrestricted Python expressions. In agent/tooling contexts this is especially dangerous because callers may trust it as low-risk and pass through untrusted input, leading to code execution under that false assumption.

VirusTotal

66/66 vendors flagged this skill as clean.

View on VirusTotal