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Security audit

SF Express

Security checks for vulnerabilities and agentic risk

Overview

Review is needed because shipment-number allocation skips confirmation and setup executes an unverified remote installer.

Before use, require confirmation of the target order and quantity when allocating child waybill numbers. Install oo separately from a verified release rather than letting setup execute mutable remote code automatically. Connecting the account allows sensitive shipment data and approved business changes to pass through OOMOL. External runtime behavior was not verified.

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
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Findings (4)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
96% confidence
Finding

The supplied command installs software from Oomol rather than performing SF Express operations. Nothing in the supplied chunk establishes that this installer is a supporting dependency for the declared functionality. The downloaded script's contents and any further effects are not visible.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
97% confidence
Finding

The setup instructions pipe a remotely fetched, mutable script directly into bash, with an equivalent download-and-execute pattern in PowerShell, without pinning or independent integrity verification. If the installer endpoint or its supply chain is compromised, attacker-controlled code could execute with the agent process's privileges and access local files or credentials; conditional execution only when the CLI is missing reduces exposure but does not remove the risk.

Content

Scanner excerpt · SKILL.md (reported line 209)May include surrounding context.

Waybill-number allocation is classified as a read, bypassing the documented confirmation requirement.

Medium
Category
Excessive Agency
Confidence
98% confidence
Finding

The untagged get_sub_waybill_nos action allocates additional child waybill numbers for an existing order, which is a state-changing operation rather than a read. Because the Safety section explicitly permits untagged actions to run directly, an agent could allocate numbers without the confirmation required for other writes, potentially causing unintended changes to shipment records.

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 230)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