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Security audit

Mailercloud

Security checks for vulnerabilities and agentic risk

Overview

Mailercloud actions have approval safeguards, but setup can execute unverified remote code and introduce undisclosed changes to other agent skills.

Review and approve a verified CLI installation before use, and review or disable its automatic installation and synchronization of other agent skills. OOMOL will handle your Mailercloud connection and requests. Keep account permissions limited and retain the stated approval checks for changes and deletions. The remote installers and exact runtime release 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 (4)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
94% confidence
Finding

The supplied chunk performs remote software installation rather than Mailercloud data operations. Although installation can be a supporting implementation detail, nothing in the supplied content connects this Oomol installer to the declared Mailercloud functionality. The downloaded script's contents are not provided, so its further behavior cannot be determined.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
97% confidence
Finding

Piping the HTTPS installer directly into bash executes mutable remote content without version pinning, integrity verification, or an opportunity for review. Compromise of the distribution endpoint could therefore result in arbitrary code execution with the invoking process's permissions; the legitimate CLI dependency explains the purpose but does not establish the downloaded script's integrity.

Content

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

The setup workflow executes downloaded installation scripts without warning about their system-level effects.

Medium
Category
Output Handling
Confidence
92% confidence
Finding

The setup instructions direct execution of downloaded shell or PowerShell scripts without explaining their local effects or requiring explicit installation approval. Such scripts execute with the invoking process's permissions and could modify files or access locally available secrets; conditional execution only when the CLI is missing reduces exposure but does not remove this 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