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Security audit

Postman

Security checks for vulnerabilities and agentic risk

Overview

Postman changes require user approval, but setup directs the agent to execute an unverified remote installer without a separate approval step.

Review setup before installing. Prefer a separately approved CLI release with verified integrity, and inspect or disable its automatic skill synchronization. Connect only the Postman account and permissions needed, and retain the explicit approval requirements for writes and deletions. The submitted skill was fully inspected, but the remote installer and hosted connector implementation were not verified. No artifact-backed malicious intent was found.

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 contains no Postman operations and instead executes an installer from an unrelated service. Nothing in the supplied content establishes that this installation supports the declared Postman functionality. The remote script's contents are not supplied, so its specific effects cannot be determined.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

The command downloads a mutable remote script and immediately executes it without a pinned version or independent integrity verification; the PowerShell alternative has the same weakness. Compromise of the installer distribution path could execute attacker-controlled code with the agent process's local privileges, exposing accessible files and credentials. The legitimate dependency and missing-CLI condition reduce exposure but do not remove this supply-chain risk.

Content

Scanner excerpt · SKILL.md (reported line 189)May include surrounding context.

The setup workflow executes remote installation scripts without warning the user about local system changes.

Medium
Category
Output Handling
Confidence
92% confidence
Finding

The fallback directs the agent to install software after a missing-command error without explicitly obtaining approval for local system changes. A user authorizing a Postman operation has not necessarily authorized executing an installer on their machine; the conditional trigger limits exposure but does not establish consent.

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 210)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