Back to skill

Security audit

espeak-ng

Security checks for vulnerabilities and agentic risk

Overview

This is a small local text-to-speech skill for espeak-ng, with normal dependency-install caution but no hidden or malicious behavior found.

Install only if you are comfortable adding the espeak-ng system package. Prefer your OS package manager, review any installer source, and treat the direct espeak-ng command examples as local shell commands that should be run only with text you intend to speak.

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
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
  • Behavioral ASTexec() Call, eval() Call, Dynamic Import
  • MCP Least PrivilegeUnderdeclared Capability, Wildcard Permission, Missing Permission Declaration
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Findings (4)

Undeclared Tool Scope

Medium
Category
MCP Least Privilege
Confidence
89% confidence
Finding

The skill exposes shell-capable usage (python ... and direct espeak-ng <text>) but does not declare any permissions or allowed-tools scope in its metadata. In an agent ecosystem, missing tool scoping can let the skill be invoked with broader execution capability than intended, reducing policy enforcement and increasing the chance of unsafe command execution paths.

Content

No source excerpt is available for this finding.

Sudo/Root Execution

Medium
Category
Privilege Escalation
Confidence
70% confidence
Finding

Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.

Content

Scanner excerpt · SKILL.md (reported line 28)May include surrounding context.

md
## Requirements
- espeak-ng must be installed on the system
- On Linux/macOS, ensure you have `espeak-ng` installed:
- Ubuntu/Debian: `sudo apt-get install espeak-ng`
- CentOS/RHEL: `sudo yum install espeak-ng`
- macOS: `brew install espeak-ng`
- windows 11 : espeak-ng.msi from https://github.com/espeak-ng/espeak-ng/releases

Sudo/Root Execution

Medium
Category
Privilege Escalation
Confidence
70% confidence
Finding

Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.

Content

Scanner excerpt · SKILL.md (reported line 29)May include surrounding context.

md
## Requirements
- espeak-ng must be installed on the system
- On Linux/macOS, ensure you have `espeak-ng` installed:
- Ubuntu/Debian: `sudo apt-get install espeak-ng`
- CentOS/RHEL: `sudo yum install espeak-ng`
- macOS: `brew install espeak-ng`
- windows 11 : espeak-ng.msi from https://github.com/espeak-ng/espeak-ng/releases

subprocess module call

Medium
Category
Dangerous Code Execution
Confidence
70% confidence
Finding

subprocess module calls execute external commands. Without careful input validation, this enables command injection.

Content

Scanner excerpt · espeak_skill.py (reported line 8)May include surrounding context.

python
def speak(text, voice="en-us", rate=100, pitch=0.5):
    command = ["espeak-ng", text, "-v", voice, "-a", str(rate), "-p", str(pitch)]
    try:
        process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        stdout, stderr = process.communicate()
        if stderr:
            print(f"Error: {stderr.decode()}")

Static analysis

No suspicious patterns detected.