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Security audit

Mailtrap

Security checks for vulnerabilities and agentic risk

Overview

Mailtrap actions have clear approval controls, but setup directs the agent to execute an unverified remote installer without separate consent.

Review and approve CLI installation separately using a verified release. Consider OOMOL's access to your Mailtrap data and the CLI's broader agent-skill synchronization before proceeding. Keep the explicit change and deletion confirmations. The remote installer and hosted connector were not inspected; 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 code contains no Mailtrap operations or demonstrated Mailtrap integration. Its sole action is executing an installer hosted by Oomol, an undeclared capability with no established supporting role in the stated purpose. The downloaded 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 pipes a remotely fetched, mutable script directly into Bash without a pinned version or independent integrity verification; the PowerShell alternative has the same trust issue. If the distribution endpoint or publishing pipeline is compromised, the script could execute arbitrary commands with the invoking user's permissions, potentially exposing local secrets or modifying files.

Content

Scanner excerpt · SKILL.md (reported line 104)May include surrounding context.

First-time setup executes downloaded installation scripts without warning about local code execution and system changes.

Medium
Category
Output Handling
Confidence
94% confidence
Finding

The fallback directs the agent to install software when the CLI is missing, without explicitly obtaining approval for local code execution or explaining the resulting system changes. Although limited to first-time setup, this can turn an ordinary Mailtrap request into execution of downloaded code with the agent process's local permissions.

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 125)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