CVE-2024-47181 – An unaligned memory access vulnerability in Con... (How to Fix)

📋 TL;DR

An unaligned memory access vulnerability in Contiki-NG's RPL implementations can cause system crashes when processing malformed IPv6 packets with odd padding. This affects IoT devices running Contiki-NG with RPL enabled and connected to an RPL instance. The impact varies by architecture but can lead to denial of service.

💻 Affected Systems

Products:

Contiki-NG operating system

Versions: All versions up to and including 4.9

Operating Systems: Contiki-NG

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when RPL implementation is enabled and device is connected to an RPL instance

📦 What is this software?

Contiki Ng by Contiki Ng

View all CVEs affecting Contiki Ng →

⚠️ Risk & Real-World Impact

🔴

Worst Case

System crash leading to device reboot or permanent failure, causing denial of service for IoT devices

🟠

Likely Case

System instability or crash requiring manual intervention to restore functionality

🟢

If Mitigated

No impact if RPL is disabled or devices are not exposed to malicious network traffic

🌐 Internet-Facing: MEDIUM - Requires specific malformed IPv6 packets but IoT devices often have limited security controls

🏢 Internal Only: LOW - Requires attacker access to internal network and ability to craft specific packets

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Requires ability to send crafted IPv6 packets to vulnerable devices

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Next release after 4.9 (not yet released)

Vendor Advisory: https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-crjw-x84h-h6x3

Restart Required: Yes

Instructions:

1. Apply changes from pull request #2962 manually
2. Recompile Contiki-NG for affected devices
3. Deploy updated firmware
4. Restart devices

🔧 Temporary Workarounds

Disable RPL

all

Disable RPL implementations if not required for device functionality

Modify Contiki-NG configuration to disable RPL

Network segmentation

all

Isolate IoT devices on separate network segments

🧯 If You Can't Patch

Implement strict network filtering for IPv6 traffic to IoT devices
Monitor devices for crashes or abnormal behavior indicating exploitation attempts

🔍 How to Verify

Check if Vulnerable:

Check if Contiki-NG version is 4.9 or earlier and RPL is enabled in configuration

Check Version:

Check Contiki-NG build configuration or firmware version

Verify Fix Applied:

Verify pull request #2962 changes are applied or device is running post-4.9 version

📡 Detection & Monitoring

Log Indicators:

System crash logs
Unexpected device reboots
RPL protocol errors

Network Indicators:

Malformed IPv6 packets with odd padding sent to IoT devices

SIEM Query:

Search for device crash events or abnormal IPv6 traffic patterns to IoT segments

📊 Metadata

CVE ID: CVE-2024-47181

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-704

Published: November 27, 2024

Last Updated: April 10, 2025

🔗 References

https://github.com/contiki-ng/contiki-ng/pull/2962 Issue Tracking,Patch
https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-crjw-x84h-h6x3 Vendor Advisory

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🔗 Related Vulnerabilities

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