CVE-2025-53627
📋 TL;DR
This CVE describes a downgrade attack vulnerability in Meshtastic firmware where direct messages can be silently decrypted using legacy symmetric encryption instead of the intended PKI encryption. Users cannot distinguish between properly encrypted messages and downgraded ones, allowing adversaries with channel keys to spoof messages. This affects all users of Meshtastic firmware versions 2.5 through 2.7.14.
💻 Affected Systems
- Meshtastic firmware
- Meshtastic Web app
- Meshtastic iOS app
- Meshtastic Android app
- Applications using Meshtastic SDK
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Adversaries with channel keys can spoof direct messages from any user, enabling impersonation attacks, misinformation campaigns, or social engineering within mesh networks.
Likely Case
Attackers who have obtained shared channel keys can inject spoofed messages that appear legitimate, compromising message integrity and confidentiality expectations.
If Mitigated
With proper controls and patching, messages are properly encrypted with PKI and users receive clear encryption status indicators.
🎯 Exploit Status
Exploitation requires knowledge of shared channel key and ability to inject crafted messages into the mesh network.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.7.15
Vendor Advisory: https://github.com/meshtastic/firmware/security/advisories/GHSA-377p-prwp-4hwf
Restart Required: Yes
Instructions:
1. Update Meshtastic firmware to version 2.7.15 or later. 2. Update all client applications (Web, iOS, Android) to latest versions. 3. Restart devices after firmware update. 4. Verify encryption indicators are now visible in applications.
🔧 Temporary Workarounds
Disable legacy encryption fallback
allConfigure systems to reject messages without proper PKI encryption flags
Rotate channel keys
allChange shared channel keys to invalidate any compromised keys attackers may possess
🧯 If You Can't Patch
- Avoid using direct messages for sensitive communications until patched
- Manually verify message authenticity through out-of-band channels for critical communications
🔍 How to Verify
Check if Vulnerable:
Check firmware version on Meshtastic devices. If version is between 2.5 and 2.7.14 inclusive, the system is vulnerable.Check Version:
Check device settings or use Meshtastic CLI: 'meshtastic --info'Verify Fix Applied:
Verify firmware version is 2.7.15 or later and check that applications now display encryption status indicators for direct messages.📡 Detection & Monitoring
Log Indicators:
- Unusual message injection patterns
- Messages from unexpected sources
- Encryption-related errors in application logs
Network Indicators:
- Suspicious message traffic patterns in mesh network
- Messages with missing or malformed encryption headers
SIEM Query:
Search for: 'meshtastic' AND ('encryption_fallback' OR 'pki_missing' OR 'legacy_encryption')