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Security audit

AppVeyor

Security checks for vulnerabilities and agentic risk

Overview

The AppVeyor operations fit the stated purpose, but setup can execute unverified installers and introduce broader agent changes without explicit approval.

Review setup before installing. Install a verified CLI release yourself, explicitly control its agent-skill synchronization, and connect AppVeyor using the narrowest available read permissions. AppVeyor requests pass through OOMOL. The review concern is uncontrolled setup and persistent agent changes; the artifact does not establish malicious intent. Remote installer behavior and server-side credential handling remain unverified.

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
  • Output HandlingUnvalidated Output Injection, Cross-Context Output, Unbounded Output
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Findings (5)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
99% confidence
Finding

The supplied command contacts cli.oomol.com, not AppVeyor, and executes the downloaded installer. Nothing in the chunk performs AppVeyor operations or establishes that this installation supports the declared purpose. The downloaded script's contents and further effects are not visible.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
87% confidence
Finding

The supplied chunk only initiates login; it contains no AppVeyor search or read operation and does not establish that the authentication targets AppVeyor. Authentication could support a larger integration, but no such connection is shown in this chunk.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

Piping a mutable HTTPS response directly into bash executes whatever code the installation endpoint supplies with the invoking user's privileges. HTTPS protects transport but does not protect against a compromised publisher or distribution endpoint; the legitimate dependency-installation context does not provide independent integrity verification.

Content

Scanner excerpt · SKILL.md (reported line 60)May include surrounding context.

The setup workflow executes downloaded installation scripts without warning about running remote code or modifying the local system.

Medium
Category
Output Handling
Confidence
94% confidence
Finding

The fallback setup instructs execution of downloaded shell and PowerShell scripts without an explicit approval or integrity-verification step. This can turn a read-only AppVeyor request into local code execution and system modification; triggering it only when the CLI is missing limits exposure but does not eliminate the risk.

Content

No source excerpt is available for this finding.

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 81)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