CVE-2023-30766 – This CVE describes a hidden functionality vulne... (How to Fix)

Q: What is the severity of CVE-2023-30766?

CVE-2023-30766 has a CVSS score of 9.8 (CRITICAL). This CVE describes a hidden functionality vulnerability in KB-AHR and KB-IRIP series devices that allows arbitrary OS command execution or device setting alteration when exploited. Affected users include organizations using these specific KB Device recorder models with outdated firmware versions. The vulnerability stems from undocumented features that can be triggered by attackers.

📋 TL;DR

This CVE describes a hidden functionality vulnerability in KB-AHR and KB-IRIP series devices that allows arbitrary OS command execution or device setting alteration when exploited. Affected users include organizations using these specific KB Device recorder models with outdated firmware versions. The vulnerability stems from undocumented features that can be triggered by attackers.

💻 Affected Systems

Products:

KB-AHR04D
KB-AHR08D
KB-AHR16D
KB-IRIP04A
KB-IRIP08A
KB-IRIP16A

Versions: KB-AHR04D prior to 91110.1.101106.78, KB-AHR08D prior to 91210.1.101106.78, KB-AHR16D prior to 91310.1.101106.78, KB-IRIP04A prior to 95110.1.100290.78A, KB-IRIP08A prior to 95210.1.100290.78A, KB-IRIP16A prior to 95310.1.100290.78A

Operating Systems: Embedded Linux/Proprietary OS

Default Config Vulnerable: ⚠️ Yes

Notes: All affected devices with default configurations are vulnerable. The vulnerability involves hidden functionality that can be triggered remotely.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete device compromise allowing attackers to execute arbitrary commands, modify device settings, potentially install persistent malware, or use the device as a pivot point into the network.

🟠

Likely Case

Attackers exploiting the vulnerability to execute commands, disrupt device functionality, or modify recording settings to hide malicious activity.

🟢

If Mitigated

Limited impact if devices are properly segmented and access controlled, though the vulnerability still exists in the firmware.

🌐 Internet-Facing: HIGH - If devices are exposed to the internet, they can be directly attacked without network access requirements.

🏢 Internal Only: HIGH - Even internally, any attacker with network access to these devices can exploit the vulnerability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

The vulnerability allows unauthenticated access to hidden functionality. While no public exploit code is confirmed, the CVSS 9.8 score suggests exploitation is straightforward once the hidden functionality is discovered.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: KB-AHR04D: 91110.1.101106.78, KB-AHR08D: 91210.1.101106.78, KB-AHR16D: 91310.1.101106.78, KB-IRIP04A: 95110.1.100290.78A, KB-IRIP08A: 95210.1.100290.78A, KB-IRIP16A: 95310.1.100290.78A

Vendor Advisory: https://www.kbdevice.com/news/%e3%83%ac%e3%82%b3%e3%83%bc%e3%83%80%e3%83%bc%e3%81%ae%e3%83%8d%e3%83%83%e3%83%88%e3%83%af%e3%83%bc%e3%82%af%e6%94%bb%e6%92%83%e3%81%ab%e5%af%be%e3%81%99%e3%82%8b%e3%82%a2%e3%83%83%e3%83%97%e3%83%87/

Restart Required: Yes

Instructions:

1. Download the appropriate firmware update from KB Device support portal. 2. Backup device configuration. 3. Upload firmware via web interface or console. 4. Apply update and restart device. 5. Verify firmware version after restart.

🔧 Temporary Workarounds

Network Segmentation

all

Isolate affected devices in separate VLANs with strict firewall rules limiting access to necessary services only.

Access Control Lists

all

Implement network ACLs to restrict access to device management interfaces to authorized IP addresses only.

🧯 If You Can't Patch

Segment devices on isolated network segments with no internet access
Implement strict firewall rules allowing only necessary traffic to/from devices

🔍 How to Verify

Check if Vulnerable:

Check device firmware version via web interface or console and compare against patched versions listed in affected systems.

Check Version:

Check via device web interface under System Information or use console command specific to each device model (consult device manual).

Verify Fix Applied:

Verify firmware version matches or exceeds the patched version numbers listed in fix_official section.

📡 Detection & Monitoring

Log Indicators:

Unexpected command execution logs
Unauthorized configuration changes
Access from unusual IP addresses to management interfaces

Network Indicators:

Unusual outbound connections from devices
Traffic to unexpected ports on devices
Multiple failed access attempts followed by successful access

SIEM Query:

Search for: (device_type:"KB-AHR" OR device_type:"KB-IRIP") AND (event_type:"configuration_change" OR event_type:"command_execution") FROM unauthorized_sources

📊 Metadata

CVE ID: CVE-2023-30766

CVSS v3 Score: 9.8 (CRITICAL)

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

Published: June 13, 2023

Last Updated: January 6, 2025

🔗 References

https://jvn.jp/en/vu/JVNVU90812349/ Third Party Advisory
https://www.kbdevice.com/news/%e3%83%ac%e3%82%b3%e3%83%bc%e3%83%80%e3%83%bc%e3%81%ae%e3%83%8d%e3%83%83%e3%83%88%e3%83%af%e3%83%bc%e3%82%af%e6%94%bb%e6%92%83%e3%81%ab%e5%af%be%e3%81%99%e3%82%8b%e3%82%a2%e3%83%83%e3%83%97%e3%83%87/ Mitigation,Vendor Advisory
https://jvn.jp/en/vu/JVNVU90812349/ Third Party Advisory
https://www.kbdevice.com/news/%e3%83%ac%e3%82%b3%e3%83%bc%e3%83%80%e3%83%bc%e3%81%ae%e3%83%8d%e3%83%83%e3%83%88%e3%83%af%e3%83%bc%e3%82%af%e6%94%bb%e6%92%83%e3%81%ab%e5%af%be%e3%81%99%e3%82%8b%e3%82%a2%e3%83%83%e3%83%97%e3%83%87/ Mitigation,Vendor Advisory

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