CVE-2025-24797: Meshtastic Firmware RCE Vulnerability

CVE-2025-24797 Overview

CVE-2025-24797 is a critical buffer overflow vulnerability in Meshtastic, an open source mesh networking solution. A fault in the handling of mesh packets containing invalid protobuf data can result in an attacker-controlled buffer overflow, allowing an attacker to hijack execution flow, potentially resulting in remote code execution. This attack does not require authentication or user interaction, as long as the target device rebroadcasts packets on the default channel.

Critical Impact

This unauthenticated remote code execution vulnerability allows attackers to completely compromise Meshtastic devices through malicious mesh packets, requiring no user interaction and affecting all devices on the default channel.

Affected Products

• Meshtastic Firmware versions prior to 2.6.2
• All Meshtastic devices configured to rebroadcast on the default channel
• Meshtastic mesh network nodes within radio range

Discovery Timeline

• 2025-04-15 - CVE-2025-24797 published to NVD
• 2025-10-03 - Last updated in NVD database

Technical Details for CVE-2025-24797

Vulnerability Analysis

This vulnerability stems from improper restriction of operations within the bounds of a memory buffer (CWE-119) when processing mesh packets. The Meshtastic firmware fails to properly validate protobuf data contained within incoming mesh packets before processing. When malformed or malicious protobuf data is received, the parsing routine does not adequately check buffer boundaries, leading to a buffer overflow condition that an attacker can control.

The attack surface is particularly dangerous because Meshtastic devices are designed to automatically receive and rebroadcast mesh packets on their configured channels. Devices operating on the default channel are especially vulnerable since attackers can transmit malicious packets without requiring any prior knowledge of custom channel configurations.

Root Cause

The root cause is insufficient input validation in the protobuf packet handling code. When the firmware receives mesh packets, it processes the embedded protobuf data without properly validating the data size and structure against expected boundaries. This allows specially crafted packets with invalid protobuf data to write beyond allocated buffer space, corrupting adjacent memory regions.

Attack Vector

The attack exploits the mesh networking protocol's packet rebroadcasting functionality. An attacker within radio range of any Meshtastic device can transmit a specially crafted mesh packet containing malicious protobuf data. The vulnerability is network-accessible because:

1. No authentication is required to send mesh packets on default channels
2. No user interaction is needed—devices automatically process received packets
3. The malicious packet propagates through the mesh network as devices rebroadcast it
4. Each device that processes the packet is vulnerable to code execution

The attacker can craft the overflow payload to hijack program execution flow, potentially gaining full control over the target device's firmware execution.

Detection Methods for CVE-2025-24797

Indicators of Compromise

• Unexpected device crashes or reboots when receiving mesh packets
• Anomalous firmware behavior or modified device configurations
• Unusual outbound network activity from Meshtastic devices
• Device memory corruption errors in debug logs

Detection Strategies

• Monitor Meshtastic device logs for repeated crashes or protobuf parsing errors
• Implement network monitoring for malformed mesh packets with oversized or invalid protobuf payloads
• Deploy firmware integrity checking to detect unauthorized code execution
• Use RF spectrum analysis to identify suspicious packet patterns targeting default channels

Monitoring Recommendations

• Enable debug logging on Meshtastic devices to capture parsing errors and crash data
• Establish baseline device behavior to identify anomalies in packet processing
• Monitor mesh network traffic patterns for injection attacks or unusual packet volumes
• Implement alerting for devices that become unresponsive or exhibit erratic behavior

How to Mitigate CVE-2025-24797

Immediate Actions Required

• Upgrade all Meshtastic firmware installations to version 2.6.2 or later immediately
• Consider disabling packet rebroadcasting on critical devices until patching is complete
• Switch devices from the default channel to a custom channel configuration
• Isolate unpatched Meshtastic devices from production mesh networks

Patch Information

This vulnerability has been fixed in Meshtastic firmware version 2.6.2. Organizations should upgrade all affected devices to this version or later. The fix addresses the buffer overflow by implementing proper boundary checking when parsing protobuf data in mesh packets. For detailed patch information, refer to the GitHub Security Advisory.

Workarounds

• Configure devices to use non-default, private channels to reduce attack surface
• Disable automatic packet rebroadcasting where operationally feasible
• Implement physical access controls to limit attacker proximity to mesh network devices
• Deploy network segmentation to isolate Meshtastic infrastructure from critical systems