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Security audit

beware-piper-tts-free

Security checks for vulnerabilities and agentic risk

Overview

This TTS skill appears to be a local text-to-speech helper, but its instructions are internally inconsistent about API keys, external services, and network behavior.

Review before installing. Treat it as a local Piper TTS skill only, do not provide API keys unless you independently confirm a real need, and inspect any setup or synthesis commands before running them because no implementation scripts are included in the package.

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
  • 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
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
  • Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Findings (8)

Intent-Code Divergence

Medium
Category
Not specified by scanner
Confidence
93% confidence
Finding

The feature list contradicts the stated limitations of the free edition, creating uncertainty about what capabilities are actually present. Such ambiguity can cause agents or users to invoke unsupported flows, install unnecessary components, or grant permissions based on incorrect expectations.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

Medium
Category
Not specified by scanner
Confidence
96% confidence
Finding

The documentation gives conflicting claims about being fully local and requiring or using API keys/LLM APIs. This is dangerous because operators may enable unnecessary secrets, network access, or trust assumptions that broaden the skill's attack surface and lead to accidental secret exposure or policy bypass.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
84% confidence
Finding

The markdown states that the free version uses only the preset en_US-kusal-medium voice, which hard-codes an English (US) locale for synthesis. While limitations can be documented, the skill does not offer a user language choice or frame this as an opt-in locale restriction, and elsewhere presents the skill as generally applicable.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
87% confidence
Finding

The line says 英文优先 and explains that Chinese reading requires a paid version, which imposes a language preference constraint in the skill behavior. This is a natural-language locale policy concern because the skill does not present the language restriction as a user choice or clearly scoped regional limitation.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

Medium
Category
Not specified by scanner
Confidence
91% confidence
Finding

The input/options section advertises adjustable voice controls while later sections state that speed, pause, and pitch are unsupported. This mismatch can cause downstream agents to pass unvalidated option fields into scripts or command lines, increasing the chance of unsafe parameter handling or broken automation.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

Medium
Category
Not specified by scanner
Confidence
89% confidence
Finding

Claiming external API integration in a skill described as local-only can mislead users into permitting outbound connectivity or treating remote behavior as expected. In security-sensitive environments, this undermines trust boundaries and may mask unintended data egress paths.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

Medium
Category
Not specified by scanner
Confidence
97% confidence
Finding

The FAQ says API keys are required, directly contradicting repeated no-API-key claims. This can lead administrators to provision secrets unnecessarily, creating avoidable secret-management risk and normalizing broader access than the skill should need.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

Low
Category
Not specified by scanner
Confidence
84% confidence
Finding

The troubleshooting table includes API authentication failure, rate limiting, gateway timeout, and network connectivity failures, even though the skill is described as local-only with zero cloud calls. These documented failure modes contradict the stated intent and imply external service usage that the manifest denies.

Content

No source excerpt is available for this finding.