Security audit

heyyumi

Security checks for vulnerabilities and agentic risk

Overview

The skill supports restaurant searches and user-confirmed reservation requests, with clearly disclosed sharing of booking details.

Confirm the venue, time, party size, and contact details before sending a reservation. Live inquiries notify venue owners. Keep API keys out of chat. HeyYumi's [privacy policy](https://heyyumi.ai/legal/privacy) states that identifiable booking details are retained for three years; consider this before sharing personal information. Hosted service behavior remains outside this artifact review.

A.I.G

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

SkillSpector

Vulnerability Patterns

Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code

Findings (1)

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 53)May include surrounding context.
On a headless host the OAuth callback returns to localhost on that host, so a user chatting from a phone usually can't finish it; suggest the API key instead (free at https://heyyumi.ai/mcp, set as HEYYUMI_API_KEY or skills.entries.heyyumi.apiKey).

Never ask the user to paste a password, key or token into chat.

bash
# list tools and full argument schemas