CVE-2026-1803: Ziroom ZHOME A0101 Auth Bypass Vulnerability

CVE-2026-1803 Overview

A default credentials vulnerability has been identified in the Ziroom ZHOME A0101 smart home device running firmware version 1.0.1.0. The vulnerability exists within the Dropbear SSH Service component, allowing remote attackers to gain unauthorized access to the device using hardcoded credentials. While the attack complexity is considered high and exploitation is difficult, the exploit has been made publicly available, increasing the risk of attacks against affected devices.

Critical Impact

Remote attackers can leverage default credentials to gain full SSH access to vulnerable Ziroom ZHOME A0101 devices, potentially compromising the entire smart home ecosystem and enabling further lateral movement within the network.

Affected Products

• Ziroom ZHOME A0101 firmware version 1.0.1.0
• Dropbear SSH Service on ZHOME A0101 devices

Discovery Timeline

• 2026-02-03 - CVE-2026-1803 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2026-1803

Vulnerability Analysis

This vulnerability falls under CWE-1392 (Use of Default Credentials), a common weakness in IoT and embedded devices where manufacturers ship products with pre-configured authentication credentials that remain unchanged after deployment. The Ziroom ZHOME A0101 smart home device contains hardcoded default credentials in its Dropbear SSH Service, which provides remote shell access to the device.

The attack is network-based, meaning any attacker with network access to the device can attempt exploitation. While the CVE description notes that attack complexity is high and exploitability is considered difficult, the public availability of exploit information significantly lowers the practical barrier to entry for attackers. Successful exploitation grants complete access to the device's operating system, enabling attackers to modify device configurations, intercept smart home communications, pivot to other network devices, or persist within the environment.

The vendor was contacted during responsible disclosure but did not respond, leaving users without an official remediation path.

Root Cause

The root cause of this vulnerability is the use of hardcoded default credentials in the Dropbear SSH Service shipped with Ziroom ZHOME A0101 devices. This insecure default configuration pattern is prevalent in IoT devices where manufacturers prioritize ease of setup over security. The credentials are embedded in the firmware and are not required to be changed during initial device setup, leaving devices vulnerable to unauthorized access throughout their operational lifetime.

Attack Vector

The attack vector is network-based, targeting the Dropbear SSH Service exposed on the Ziroom ZHOME A0101 device. An attacker with network visibility to the device can:

1. Identify vulnerable devices through network scanning for SSH services
2. Attempt authentication using known default credentials
3. Upon successful authentication, gain shell access to the device
4. Execute arbitrary commands, modify configurations, or establish persistent access

Technical details and proof-of-concept information are available in the GitHub SSH Backdoor Vulnerability documentation. Due to the sensitive nature of this vulnerability in IoT devices, specific credentials are not reproduced here.

Detection Methods for CVE-2026-1803

Indicators of Compromise

• Unexpected SSH connection attempts or successful authentications to ZHOME A0101 devices
• Unusual outbound network traffic originating from smart home devices
• Modified system files or configurations on affected devices
• New user accounts or SSH keys added to the device without authorization

Detection Strategies

• Monitor network traffic for SSH connections to Ziroom ZHOME devices from unexpected sources
• Implement network segmentation and firewall rules to detect unauthorized access attempts to IoT devices
• Deploy intrusion detection systems (IDS) with signatures for default credential exploitation attempts
• Review authentication logs on network devices for connections to ZHOME device IP addresses

Monitoring Recommendations

• Establish baseline network behavior for smart home devices and alert on deviations
• Implement continuous monitoring of SSH authentication events across the network
• Configure alerts for any successful SSH authentication to IoT device segments
• Conduct periodic vulnerability assessments of IoT devices within the environment

How to Mitigate CVE-2026-1803

Immediate Actions Required

• Disable the Dropbear SSH Service on affected Ziroom ZHOME A0101 devices if remote access is not required
• Isolate affected devices on a separate network segment with restricted access
• Implement firewall rules to block external SSH access to vulnerable devices
• Change default credentials immediately if the device supports credential modification
• Monitor affected devices for signs of compromise

Patch Information

No official patch is currently available from Ziroom. The vendor was contacted during responsible disclosure but did not respond. Users should monitor official Ziroom channels for any future firmware updates addressing this vulnerability. Additional details can be found in the VulDB advisory.

Workarounds

• Disable SSH service entirely on the device if remote management is not required
• Place affected devices behind a firewall blocking port 22 from untrusted networks
• Implement network access control lists (ACLs) to restrict which hosts can connect to the device
• Consider replacing vulnerable devices with alternatives from vendors with better security practices
• Use a VPN to access the device remotely rather than exposing SSH directly

# Example firewall rule to block external SSH access to ZHOME devices
# Replace 192.168.1.100 with your ZHOME device IP address
iptables -A INPUT -p tcp --dport 22 -d 192.168.1.100 -j DROP
iptables -A FORWARD -p tcp --dport 22 -d 192.168.1.100 -j DROP

# Alternative: Block SSH from untrusted networks, allow only from management VLAN
iptables -A INPUT -p tcp --dport 22 -d 192.168.1.100 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -d 192.168.1.100 -j DROP