CVE-2023-23906 – This vulnerability allows remote unauthenticate... (How to Fix)

Q: What is the severity of CVE-2023-23906?

CVE-2023-23906 has a CVSS score of 7.5 (HIGH). This vulnerability allows remote unauthenticated attackers to execute critical functions on SkyBridge MB-A100/110 devices without authentication. Attackers can reboot the product, potentially causing denial of service. Organizations using SkyBridge MB-A100/110 firmware version 4.2.0 or earlier are affected.

📋 TL;DR

This vulnerability allows remote unauthenticated attackers to execute critical functions on SkyBridge MB-A100/110 devices without authentication. Attackers can reboot the product, potentially causing denial of service. Organizations using SkyBridge MB-A100/110 firmware version 4.2.0 or earlier are affected.

💻 Affected Systems

Products:

SkyBridge MB-A100
SkyBridge MB-A110

Versions: 4.2.0 and earlier

Operating Systems: Embedded firmware

Default Config Vulnerable: ⚠️ Yes

Notes: All configurations of affected firmware versions are vulnerable. No special configuration required for exploitation.

📦 What is this software?

Skybridge Mb A100 Firmware by Seiko Sol

View all CVEs affecting Skybridge Mb A100 Firmware →

Skybridge Mb A110 Firmware by Seiko Sol

View all CVEs affecting Skybridge Mb A110 Firmware →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Attackers could repeatedly reboot the device, causing sustained denial of service and disrupting network operations.

🟠

Likely Case

Remote attackers reboot the device, causing temporary service disruption until manual intervention.

🟢

If Mitigated

With proper network segmentation and access controls, impact is limited to denial of service within isolated network segments.

🌐 Internet-Facing: HIGH - Devices exposed to the internet can be rebooted by any remote attacker without authentication.

🏢 Internal Only: MEDIUM - Internal attackers or compromised internal systems could reboot devices, but requires network access.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

The vulnerability requires no authentication and minimal technical skill to exploit via network requests.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Version 4.2.1 or later

Vendor Advisory: https://www.seiko-sol.co.jp/archives/73969/

Restart Required: Yes

Instructions:

1. Download firmware version 4.2.1 or later from Seiko Solutions website. 2. Upload firmware to device via web interface. 3. Apply firmware update. 4. Reboot device to complete installation.

🔧 Temporary Workarounds

Network Segmentation

all

Restrict network access to SkyBridge devices to trusted management networks only

Firewall Rules

all

Block external access to SkyBridge management interfaces

🧯 If You Can't Patch

Isolate SkyBridge devices on separate VLAN with strict access controls
Implement network monitoring for reboot attempts and unauthorized access

🔍 How to Verify

Check if Vulnerable:

Check firmware version in device web interface. If version is 4.2.0 or earlier, device is vulnerable.

Check Version:

Check via web interface at http://[device-ip]/ or via SSH if enabled

Verify Fix Applied:

Verify firmware version is 4.2.1 or later in device web interface after update.

📡 Detection & Monitoring

Log Indicators:

Unexpected reboot events
Unauthenticated access attempts to management functions

Network Indicators:

HTTP requests to reboot endpoints from unauthorized sources

SIEM Query:

source="skybridge" AND (event="reboot" OR event="unauthorized_access")

📊 Metadata

CVE ID: CVE-2023-23906

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-306

Published: May 10, 2023

Last Updated: January 28, 2025

🔗 References

https://jvn.jp/en/jp/JVN40604023/ Third Party Advisory
https://www.seiko-sol.co.jp/archives/73969/ Vendor Advisory
https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a100/ Product
https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a130/ Product
https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a200/ Product
https://www.seiko-sol.co.jp/products/skyspider/skyspider_download/mb-r210/ Product
https://jvn.jp/en/jp/JVN40604023/ Third Party Advisory
https://www.seiko-sol.co.jp/archives/73969/ Vendor Advisory
https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a100/ Product
https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a130/ Product
https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a200/ Product
https://www.seiko-sol.co.jp/products/skyspider/skyspider_download/mb-r210/ Product

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