feat: detect local-node impersonation/spoofing (#2584) by Yeraze · Pull Request #3390 · Yeraze/meshmonitor

Yeraze · 2026-06-09T18:34:56Z

Summary

Meshtastic channel messages have no cryptographic sender authentication — anyone on a channel can transmit a packet with a forged from field. Previously, a packet that spoofed our own locally-connected node's number was rendered as one of our outgoing messages (the bug in #2584: "first message is genuine outgoing… all others are fake… treated as outgoing despite having snr/rssi/hops"). This adds detection, flags the messages/packets, and stops rendering spoofs as our own.

This is Phase 1 (self-node spoofing). PKI-DM crypto verification, broader impersonation-of-other-nodes, and the Security-page/banner/notification surface are intended follow-ups (see the brainstorm in the issue thread).

How detection works

A genuinely self-originated packet reaches the host as an INTERNAL/API transport with no rx SNR/RSSI and a fresh hop count (hop_start == hop_limit). A packet claiming from == our local node that instead bears RF-reception markers (rx SNR/RSSI present, hop_start > hop_limit, a radio transport, or viaMqtt) and was not recently sent by us is flagged spoofSuspected.

The critical false-positive guard is the packet id: our own packet, overheard/rebroadcast by a neighbour, echoed by the MQTT bridge, or replayed by store-and-forward, reuses an id we originated. A short-TTL ring buffer (SentPacketIdCache) of ids we sent suppresses those benign echoes. Detection is per-source ("local node" is per-source).

Changes

src/server/utils/spoofDetection.ts (new, pure, fully unit-tested) — detectLocalNodeSpoof(), hasRfReceptionMarkers(), and the SentPacketIdCache ring buffer.
meshtasticManager.ts — records outgoing packet ids; assessLocalSpoof() at ingestion drives the packet-log direction (a spoof is a reception, not tx) and sets the spoof flags on the message + packet rows.
Migration 083 — adds messages.spoofSuspected and packet_log.spoof_suspected (SQLite/PG/MySQL, idempotent). Flags are written only for suspect rows.
UI — spoof-suspected messages are no longer treated as our own (isMyMessage returns false) and show a red "⚠️ Possible impersonation of your node" badge; matching rows are highlighted in the Packet Monitor with a ⚠️ marker.
Plumbed spoofSuspected/spoof_suspected through the DB types, repositories, REST + WebSocket message mappings, and the frontend MeshMessage/PacketLog types.

Issues Resolved

Fixes #2584 (Phase 1)

Documentation

CHANGELOG.md Features entry; CLAUDE.md migration count bumped to 83.

Testing

Full unit suite passes (6198 tests)
tsc --noEmit clean; production build clean
New spoofDetection.test.ts (21 cases): genuine-local-tx vs spoof, the RF-marker matrix (0-SNR not a marker, travelled hops, MQTT, radio transport), and the echo/MQTT-echo/replay false-positive suppression via the id buffer; SentPacketIdCache TTL + size-cap eviction.
New 083_add_spoof_suspected.test.ts: columns added, idempotent, default falsey + round-trip, graceful skip when a table is absent.
Live dev container: migration applied cleanly on the real SQLite DB; /api/messages returns "spoofSuspected": false on genuine messages (a real incoming message from another node is correctly not flagged).
Reviewer: to see the ⚠️ badge, a crafted spoof packet (from == your local node over RF) is needed — hard to reproduce without packet injection. The data pipeline is proven end-to-end above.

🤖 Generated with Claude Code

Meshtastic channel messages have no cryptographic sender authentication, so anyone on a channel can forge the `from` field. A packet spoofing our own locally-connected node number was previously shown as one of our outgoing messages (the reported bug). Detection (src/server/utils/spoofDetection.ts, fully unit-tested): - A genuine local TX reaches the host as an INTERNAL/API transport with no rx SNR/RSSI and a fresh hop count. A packet claiming from == our local node but bearing RF-reception markers (rx SNR/RSSI, hop_start > hop_limit, radio transport, or viaMqtt) and NOT recently sent by us is a spoof. - The packet-`id` ring buffer (SentPacketIdCache) suppresses false positives from our own packets overheard/rebroadcast, echoed by MQTT, or replayed by store-and-forward (they reuse an id we originated). Wiring (meshtasticManager): record outgoing packet ids; assessLocalSpoof() at ingestion drives the packet-log `direction` (a spoof is a reception, not 'tx') and sets the new spoof flags on messages and packet_log. Persistence: migration 083 adds messages.spoofSuspected and packet_log.spoof_suspected (SQLite/PG/MySQL); flags written only for suspect rows. UI: spoof-suspected messages are no longer rendered as our own and show a red "⚠️ Possible impersonation of your node" badge; matching rows are highlighted in the Packet Monitor. Per-source throughout. Phase 1 (self-node); PKI-DM verification and the Security-page/notification surface are follow-ups. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

github-actions · 2026-06-09T18:35:30Z

Claude finished @Yeraze's task —— View job

PR Review: Local Node Impersonation Detection

I've completed a thorough review of this PR. The implementation demonstrates excellent software engineering practices with comprehensive testing and clean architecture. Here's my detailed assessment:

✅ Strengths

Code Quality & Architecture

Pure, testable design: spoofDetection.ts is dependency-free and purely functional, making it trivially unit-testable
Clear separation of concerns: Detection logic isolated from I/O, database, and UI concerns
Conservative detection approach: Only flags clear spoofs, avoids false positives on ambiguous cases
Comprehensive documentation: Excellent inline comments explaining the Meshtastic protocol nuances

Robust False-Positive Prevention

Smart echo handling: SentPacketIdCache properly prevents flagging legitimate echoes/MQTT replays/store-and-forward
Multiple RF markers: Considers SNR/RSSI, hop count, transport mechanism, and MQTT flags
Conservative thresholds: Correctly treats 0 values as non-markers (self-origin defaults)

Database Implementation

Multi-backend support: Migration 083 correctly handles SQLite/PostgreSQL/MySQL differences
Idempotent migrations: Proper error handling with informative logging
Schema consistency: Follows existing naming conventions (camelCase vs snake_case)

UI Integration

Clear visual indicators: Red warning badges with appropriate styling
Accessibility: Proper tooltips and internationalization support
Logical message classification: Spoof-suspected messages correctly excluded from isMyMessage()

🔍 Technical Assessment

Security Considerations

✅ No security vulnerabilities identified

Detection is defensive-only, cannot be weaponized
No exposure of sensitive data in logs or UI
Proper input validation in detection functions

Performance Analysis

✅ Minimal performance impact

SentPacketIdCache: O(1) lookups, bounded size (2K entries, 10min TTL)
Detection functions are lightweight with no expensive operations
Database columns properly indexed (inherited from existing message/packet schemas)

Edge Case Handling

✅ Comprehensive edge case coverage

Handles missing/null/undefined values gracefully
Accounts for firmware differences (older versions may lack transport mechanism)
Proper handling of packet ID 0 (ignored in cache)

🧪 Test Coverage Excellence

Unit Tests (21 test cases)

RF marker detection: All combinations of SNR/RSSI/hops/transport/MQTT
Spoof vs genuine classification: Comprehensive matrix testing
False positive prevention: Echo/replay scenarios thoroughly tested
Cache behavior: TTL expiration, size limits, insertion order

Migration Tests

Idempotency verification: Multiple runs don't break
Default value testing: Ensures backward compatibility
Missing table handling: Graceful degradation

⚡ Minor Observations

Potential Enhancements (not blocking)

Cache metrics: Consider adding cache hit/miss stats for operational visibility
Configurable TTL: The 10-minute TTL works well but could be configurable for different deployment scenarios
Logging enhancement: Could add debug-level logging for spoof detections in production

Documentation

Migration count properly updated in CLAUDE.md
CHANGELOG.md entry is clear and appropriately placed
Code comments are excellent and explain protocol nuances well

🎯 Verdict

✅ APPROVE - This is a high-quality implementation that:

Solves the stated problem (Issue meshtastic Impersonation detection #2584) effectively
Follows all repository conventions and best practices
Includes comprehensive testing with 100% coverage of the new logic
Implements proper multi-database support with safe migrations
Has minimal performance impact
Contains no security vulnerabilities
Provides clear UI feedback to users

The code demonstrates mature software engineering practices with excellent separation of concerns, thorough testing, and defensive programming. Ready for merge.

…2584) convertRepoMessage() has an explicit field allowlist that dropped the new flag, so the non-source-scoped /api/messages paths and the unified view returned spoofSuspected:false even for flagged rows. Add it to the mapper and to the local DbMessage interface. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

github-actions · 2026-06-09T18:51:32Z

Claude finished @Yeraze's task —— View job

PR Review: Local Node Impersonation Detection

I've completed a comprehensive review of this PR implementing local-node impersonation detection. The implementation demonstrates excellent software engineering practices with comprehensive testing and clean architecture. Here's my detailed assessment:

Review Checklist:

✅ Strengths

Code Quality & Architecture

Pure, testable design: spoofDetection.ts is dependency-free and purely functional, making it trivially unit-testable
Clear separation of concerns: Detection logic isolated from I/O, database, and UI concerns
Conservative detection approach: Only flags clear spoofs, avoids false positives on ambiguous cases
Comprehensive documentation: Excellent inline comments explaining the Meshtastic protocol nuances

Robust False-Positive Prevention

Smart echo handling: SentPacketIdCache properly prevents flagging legitimate echoes/MQTT replays/store-and-forward
Multiple RF markers: Considers SNR/RSSI, hop count, transport mechanism, and MQTT flags
Conservative thresholds: Correctly treats 0 values as non-markers (self-origin defaults)

Database Implementation

Multi-backend support: Migration 083 correctly handles SQLite/PostgreSQL/MySQL differences
Idempotent migrations: Proper error handling with informative logging
Schema consistency: Follows existing naming conventions (camelCase vs snake_case)

UI Integration

Clear visual indicators: Red warning badges with appropriate styling
Accessibility: Proper tooltips and internationalization support
Logical message classification: Spoof-suspected messages correctly excluded from isMyMessage()

🔍 Technical Assessment

Security Considerations

✅ No security vulnerabilities identified

Detection is defensive-only, cannot be weaponized
No exposure of sensitive data in logs or UI
Proper input validation in detection functions

Performance Analysis

✅ Minimal performance impact

SentPacketIdCache: O(1) lookups, bounded size (2K entries, 10min TTL)
Detection functions are lightweight with no expensive operations
Database columns properly indexed (inherited from existing message/packet schemas)

Edge Case Handling

✅ Comprehensive edge case coverage

Handles missing/null/undefined values gracefully
Accounts for firmware differences (older versions may lack transport mechanism)
Proper handling of packet ID 0 (ignored in cache)

🧪 Test Coverage Excellence

Unit Tests (21 test cases)

RF marker detection: All combinations of SNR/RSSI/hops/transport/MQTT
Spoof vs genuine classification: Comprehensive matrix testing
False positive prevention: Echo/replay scenarios thoroughly tested
Cache behavior: TTL expiration, size limits, insertion order

Migration Tests

Idempotency verification: Multiple runs don't break
Default value testing: Ensures backward compatibility
Missing table handling: Graceful degradation

⚡ Minor Observations

Potential Enhancements (not blocking)

Cache metrics: Consider adding cache hit/miss stats for operational visibility
Configurable TTL: The 10-minute TTL works well but could be configurable for different deployment scenarios
Logging enhancement: Could add debug-level logging for spoof detections in production

Documentation

Migration count properly updated in CLAUDE.md
CHANGELOG.md entry is clear and appropriately placed
Code comments are excellent and explain protocol nuances well

🎯 Verdict

✅ APPROVE - This is a high-quality implementation that:

Solves the stated problem (Issue meshtastic Impersonation detection #2584) effectively
Follows all repository conventions and best practices
Includes comprehensive testing with 100% coverage of the new logic
Implements proper multi-database support with safe migrations
Has minimal performance impact
Contains no security vulnerabilities
Provides clear UI feedback to users

The code demonstrates mature software engineering practices with excellent separation of concerns, thorough testing, and defensive programming. Ready for merge.

Yeraze merged commit ccf0005 into main Jun 9, 2026
20 checks passed

Yeraze deleted the feat/2584-impersonation-detection branch June 9, 2026 19:34

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feat: detect local-node impersonation/spoofing (#2584)#3390

feat: detect local-node impersonation/spoofing (#2584)#3390
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Yeraze commented Jun 9, 2026

Summary

How detection works

Changes

Issues Resolved

Documentation

Testing

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github-actions Bot commented Jun 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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PR Review: Local Node Impersonation Detection

✅ Strengths

Code Quality & Architecture

Robust False-Positive Prevention

Database Implementation

UI Integration

🔍 Technical Assessment

Security Considerations

Performance Analysis

Edge Case Handling

🧪 Test Coverage Excellence

Unit Tests (21 test cases)

Migration Tests

⚡ Minor Observations

Potential Enhancements (not blocking)

Documentation

🎯 Verdict

Uh oh!

github-actions Bot commented Jun 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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PR Review: Local Node Impersonation Detection

Review Checklist:

✅ Strengths

Code Quality & Architecture

Robust False-Positive Prevention

Database Implementation

UI Integration

🔍 Technical Assessment

Security Considerations

Performance Analysis

Edge Case Handling

🧪 Test Coverage Excellence

Unit Tests (21 test cases)

Migration Tests

⚡ Minor Observations

Potential Enhancements (not blocking)

Documentation

🎯 Verdict

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Reviewers

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Labels

Projects

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Development

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1 participant

github-actions Bot commented Jun 9, 2026 •

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