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Security audit

Korta Model Usage

Security checks for vulnerabilities and agentic risk

Overview

This skill coherently summarizes local CodexBar model cost data and does not show hidden, persistent, destructive, or deceptive behavior.

Install only if you are comfortable with CodexBar reading local Codex or Claude usage logs to compute cost summaries, and review the third-party CodexBar Homebrew cask source if that dependency is not already trusted in your environment.

Vulnerability Patterns
  • Skill Instruction HijackingAlters the agent's session goals or safety constraints when the skill loads
  • Agent Memory PoisoningWrites attacker-controlled rules into memory that affect later sessions
  • Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review
  • Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally
  • Unauthorized Access and Privilege EscalationObtains permissions beyond the task's legitimate needs
Vulnerability Patterns
  • Behavioral ASTexec() Call, eval() Call, Dynamic Import
  • MCP Least PrivilegeUnderdeclared Capability, Wildcard Permission, Missing Permission Declaration
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Findings (2)

Undeclared Tool Scope

Medium
Category
MCP Least Privilege
Confidence
91% confidence
Finding

The skill invokes shell commands and reads local files but does not declare any explicit tool scope such as permissions or allowed-tools. That creates an authorization gap: an agent may execute broader shell or file access than reviewers expect, increasing the chance of unintended local data exposure or command execution beyond the skill's narrow purpose.

Content

No source excerpt is available for this finding.

subprocess module call

Medium
Category
Dangerous Code Execution
Confidence
70% confidence
Finding

subprocess module calls execute external commands. Without careful input validation, this enables command injection.

Content

Scanner excerpt · scripts/model_usage.py (reported line 27)May include surrounding context.

python
def run_codexbar_cost(provider: str) -> List[Dict[str, Any]]:
    cmd = ["codexbar", "cost", "--format", "json", "--provider", provider]
    try:
        output = subprocess.check_output(cmd, text=True)
    except FileNotFoundError:
        raise RuntimeError("codexbar not found on PATH. Install CodexBar CLI first.")
    except subprocess.CalledProcessError as exc:

Static analysis

No suspicious patterns detected.