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Security audit

hub-oss-file-upload

Security checks for vulnerabilities and agentic risk

Overview

This skill uploads a user-requested workspace file to an internal Hub file service and returns a temporary link, with the behavior disclosed and bounded.

Install only if you want agents to create temporary external download links for workspace files. Treat returned links as shareable outside the workspace for about 7 days, and avoid requesting links for files containing secrets or private data unless sharing is intended.

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
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Trigger AbuseOverly Broad Trigger, Shadow Command Trigger, Keyword Baiting Trigger
  • MCP Least PrivilegeUnderdeclared Capability, Wildcard Permission, Missing Permission Declaration
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Findings (5)

Undeclared Tool Scope

Medium
Category
MCP Least Privilege
Confidence
91% confidence
Finding

The skill invokes a shell script to upload workspace files but declares no explicit tool scope or allowed-tools boundary. That creates an authorization gap: an agent may execute shell-capable behavior without clear least-privilege constraints, increasing the chance of unintended file access or exfiltration if the skill is triggered improperly.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
99% confidence
Finding

The description requires '对用户只说简体中文短句', which forces a specific language regardless of user preference. This is a natural-language policy issue because it does not offer any user opt-in or language selection.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
98% confidence
Finding

The line states '对用户只说简体中文短句。', again imposing a single language with no user choice. This reinforces a locale/language restriction that is not documented as optional or region-specific.

Content

No source excerpt is available for this finding.

Vague Triggers

Medium
Category
Not specified by scanner
Confidence
95% confidence
Finding

The skill explicitly broadens activation beyond enumerated phrases ('不限于某几个固定词,下面都算'), which makes triggering ambiguous and overbroad for a capability that uploads files to an external OSS and returns a public link. Overbroad matching raises the risk of accidental activation and unintended data exfiltration from the workspace when a user merely discusses files or sharing in a non-authorizing context.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Low
Category
Not specified by scanner
Confidence
96% confidence
Finding

The comments and all user-facing error/output strings in this script are written in Chinese, and there is no indication that the skill is region-specific or that users can opt into another language. That creates a natural-language locale policy concern because the skill effectively forces one language for interaction.

Content

No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.