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Security audit

Wc Chars Tool

Security checks for vulnerabilities and agentic risk

Overview

This skill is a simple character counter with overstated documentation but no evidence of hidden, persistent, or data-stealing behavior.

Install this only if you need a minimal stdin-based character counter. Do not rely on the advertised file input, option flags, CJK-only counts, grapheme counts, JSON output, or detailed breakdowns unless the skill is updated to implement them.

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 (2)

Tp4

High
Category
MCP Tool Poisoning
Confidence
98% confidence
Finding

The declared description promises several distinct text-analysis capabilities, including total, non-whitespace, CJK, and Unicode-aware character counts. The actual code only reads stdin and prints one basic length value. While that partially matches the 'total characters' portion, it omits the other advertised metrics and broader analysis features, so the description materially overstates the skill's behavior.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

Medium
Category
Not specified by scanner
Confidence
98% confidence
Finding

The manifest describes counting total, non-whitespace, CJK, and Unicode-aware character counts, implying multiple distinct metrics. The code only reads stdin and prints a single len(...) value, so the implemented behavior is materially narrower than the stated functionality.

Content

No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.