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Security audit

Builder.io

Security checks for vulnerabilities and agentic risk

Overview

Builder.io changes require confirmation, but setup directs the agent to execute unverified remote code without a separate approval step.

Review the setup behavior before installing. Prefer a separately approved, verified CLI installation and review or disable its automatic agent-skill synchronization using the publisher's documented controls. OOMOL will mediate Builder.io access, so connect only the intended account and permissions. Keep the existing confirmations for content changes and deletion. The remote installers and hosted connector implementation remain unverified; no malicious behavior was established.

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 (4)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
99% confidence
Finding

The supplied command targets an Oomol installer, not Builder.io resources, and executes the downloaded script locally. Nothing in the supplied chunk establishes this installation as a supporting requirement for Builder.io. The remote script's further behavior cannot be determined from this chunk.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

The command executes a remotely downloaded, mutable script directly in Bash without a pinned version, integrity verification, or inspection; the PowerShell alternative uses the same download-and-execute approach. Compromise of the installer distribution could therefore execute attacker-controlled code with the invoking account's privileges, exposing local data and credentials; legitimate dependency setup and HTTPS do not eliminate this supply-chain risk.

Content

Scanner excerpt · SKILL.md (reported line 59)May include surrounding context.

Fallback installation executes downloaded scripts without warning the user about system changes.

Medium
Category
Output Handling
Confidence
94% confidence
Finding

The missing-command fallback instructs installation without requiring disclosure or approval for executing an installer and changing the local environment. Although conditional and related to a legitimate dependency, permission to operate on Builder.io data does not necessarily authorize installing software; the write-confirmation rules cover Builder.io state, not local installation.

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 80)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