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Security audit

Customer.io

Security checks for vulnerabilities and agentic risk

Overview

Customer.io changes require your approval, but automatic setup runs unpinned remote installers and under-discloses possible changes to other agent skills.

Before enabling this skill, install a pinned, verified CLI yourself and review or disable its automatic synchronization of other agent skills. Check OOMOL's handling of customer data and connected-account permissions, and retain the explicit approvals for writes and deletions. The remote installers and 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
96% confidence
Finding

The supplied chunk performs remote script execution rather than any visible Customer.io operation. Installing dependencies can be a supporting implementation detail, but nothing provided establishes that this Oomol installer supports the declared Customer.io functionality. The assessment is limited to the visible download-and-execute behavior; the remote script's further actions are unknown.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
99% confidence
Finding

Piping a mutable remote installer directly into bash executes its contents without prior inspection or cryptographic verification of a specific release. HTTPS protects transport but does not prevent a compromised distribution endpoint from supplying malicious code; the conditional setup path limits exposure but still permits execution with the user's local privileges.

Content

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

CLI setup instructs execution of remote installation scripts without a system-integrity warning or user approval.

Medium
Category
Output Handling
Confidence
96% confidence
Finding

The setup instructions direct execution of downloaded shell or PowerShell code without explicit installation approval or an integrity-verification step. A legitimate dependency requirement explains the behavior but does not authorize arbitrary local code execution; a compromised installer could access files and credentials with the invoking user's privileges.

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 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