Back to skill

Security audit

FUTA Express package tracking skill (VN)

Security checks for vulnerabilities and agentic risk

Overview

This skill does package tracking as described, but it also tells the agent to reveal full shipment personal details, including phone numbers and government ID fields, without adequate limits.

Review before installing. The skill is not showing evidence of code execution, persistence, or deception, but it may reveal personal shipment information to anyone who supplies a valid tracking code. Prefer a version that masks phone numbers, omits government ID fields, and limits output to shipment status, route, timestamps, and non-sensitive service details.

Vulnerability Patterns
  • Insecure Skill Coding PracticesFinds exploitable flaws such as hardcoded secrets or command injection
  • 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
Findings (1)

T09 · Insecure Skill Coding Practices

Warning
Location
SKILL.md:79
Finding

Excessive Disclosure of Shipment-Related Personal Information

Content
View full analysis
• SĐT: • CMND/CCCD: • Thời gian nhận: ``` ```markdown ## Important Rules - **NEVER translate Vietnamese values** - status names, department names, everything stays in Vietnamese - Format currency with periods (e.g., 350.000đ) - Hide partial phone/ID info if present (masked with X or shown as is from API) - Show timestamps in readable format (YYYY-MM-DD HH:MM) - Display all meaningful data from the response ## Error Handling - If `data.bill_id` is 0: Tracking code not found - If `data.packages` is empty: No package details available - Always show the full response data even if some fields are empty ``` ### Technical Analysis The skill explicitly directs the agent to retrieve and display sender and recipient names, phone numbers, and the actual recipient's government identity value. Its masking requirement is ineffective because it permits values to be “shown as is from API.” The additional instructions to display all meaningful data and always show the full response further undermine data minimization and may expose sensitive fields not explicitly documented by the skill. A parcel-tracking response should normally disclose only information necessary to communicate shipment status. Full phone numbers, government identity values, and unrestricted API response data are not necessary for that purpose. T ...[truncated 1790 chars]
Remediation
View remediation
Vulnerability Patterns
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
  • Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
Findings (5)

Ssd 3

High
Category
Not specified by scanner
Confidence
98% confidence
Finding

The output template directs disclosure of highly sensitive data, including full phone numbers and government ID numbers, and instructs the agent to show all meaningful response data. In this context, the danger is amplified because package-tracking APIs are often accessible with only a tracking code, so the skill could become a convenient interface for unauthorized personal-data exposure.

Content

No source excerpt is available for this finding.

External Transmission

Medium
Category
Data Exfiltration
Confidence
50% confidence
Finding

Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

Content

Scanner excerpt · SKILL.md (reported line 15)May include surrounding context.

API Endpoint

text
https://api.futaexpress.vn/bo-operation/f1/full-bill-by-code-public/<tracking_code>

Tracking Workflow

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
97% confidence
Finding

The instruction Keep all values in original Vietnamese - DO NOT translate imposes a language constraint. Because the skill does not provide user opt-in or explain a necessary locale-specific compliance reason, this is a natural-language policy violation under the language/locale rule.

Content

No source excerpt is available for this finding.

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
95% confidence
Finding

The skill explicitly instructs the agent to display personally identifiable information from the carrier API, including sender/recipient names and phone numbers, without any verification, minimization, or user warning. In a package-tracking context, a tracking code may be shared, guessed, or exposed to unintended parties, so returning full PII materially increases privacy and social-engineering risk.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
97% confidence
Finding

The rule NEVER translate Vietnamese values is a repeated language restriction that does not offer the user a language choice. This forces a specific locale behavior rather than accommodating user preference.

Content

No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.