2025-04 · 2025-Q2
MCP Tool Poisoning / WhatsApp Data Exfiltration
Layer tags: not yet tagged.
Target
WhatsApp MCP server / MCP ecosystem
Impact
Complete WhatsApp message history exfiltration; 5.5% of MCP servers exhibit tool poisoning; 33% allow unrestricted network access
Root Cause
Hidden instructions in MCP tool descriptions; no runtime integrity verification; tools can mutate definitions post-install