mcp-ssh-tool has file transfer path policy bypass and bearer token comparison hardening

Summary

mcp-ssh-tool has released version 2.1.1 with security hardening for transfer path authorization and HTTP bearer authentication.

The release addresses:

• insufficient local path policy enforcement in transfer-related filesystem handling
• incomplete canonicalization and segment-boundary handling for deny-prefix path policy checks
• non-constant-time HTTP bearer token comparison

Impact

Affected versions may allow policy bypass in transfer path handling under specific configurations, and may expose a timing side channel in bearer-token comparison for HTTP deployments.

Patched Version

Upgrade to mcp-ssh-tool >= 2.1.1.

npm install -g mcp-ssh-tool@latest

Workarounds

For deployments that cannot immediately upgrade:

• avoid exposing HTTP transport beyond loopback
• use strict filesystem policy configuration
• avoid granting MCP clients access to sensitive local transfer paths
• monitor audit logs for unexpected transfer operations

Credits

Reported by dodge1218.