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Security audit

Heartbeat

Security checks for vulnerabilities and agentic risk

Overview

The Heartbeat features match the description, but automatic setup executes unverified remote code and warrants review.

Review and install a verified CLI separately before enabling this skill, and prevent automatic execution of its remote installer fallback. Review the CLI's agent-skill syncing behavior and connect only the intended Heartbeat account. No malicious behavior was established; the Review verdict concerns installation control and an uninspected external dependency.

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
  • Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • 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 (4)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
98% confidence
Finding

The read-oriented skill conditionally instructs the agent to install a CLI by executing remotely fetched code, expanding its effects beyond reading Heartbeat data. Installing a documented dependency is not inherently deceptive, but executing an unverified installer without explicit approval creates a supply-chain code-execution risk; this overlaps with the SC2 finding.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
84% confidence
Finding

The supplied chunk performs only a CLI login and contains no Heartbeat-specific operations or connection to the declared functionality. Authentication could support a Heartbeat integration, but that relationship is not established here; as supplied, the implementation has a materially different primary purpose.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
99% confidence
Finding

The command pipes an unpinned remote installer directly into Bash, allowing the fetched script to execute with the agent process's privileges without integrity verification or review. HTTPS and the restriction to missing-CLI situations reduce exposure but do not prevent malicious code execution if the distribution endpoint is compromised; the PowerShell example has the same risk.

Content

Scanner excerpt · SKILL.md (reported line 61)May include surrounding context.

Autonomous Decision Making

Medium
Category
Excessive Agency
Confidence
80% confidence
Finding

Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.

Content

Scanner excerpt · SKILL.md (reported line 82)May include surrounding context.

md
- **`OOMOL_INSUFFICIENT_CREDIT`** — OOMOL billing stop. Recharge at `https://console.oomol.com/billing/token-recharge` before retrying.

- **HTTP 402 without `OOMOL_INSUFFICIENT_CREDIT`** — the third-party account itself has no active plan or credit. Report the provider error message as is; do not ask the user to recharge OOMOL.

## Resources