CVE-2017-18371
The ZyXEL P660HN-T1A v2 TCLinux Fw #7.3.37.6 router distributed by TrueOnline has three user...
The ZyXEL P660HN-T1A v2 TCLinux Fw #7.3.37.6 router distributed by TrueOnline has three user accounts with default passwords, including two hardcoded service accounts: one with the username true and password true, and another with the username supervisor and password zyad1234. These accounts can be used to login to the web interface, exploit authenticated command injections, and change router settings for malicious purposes.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
9.8
The ZyXEL P660HN-T1A v2 TCLinux Fw #7.3.37.6 router distributed by TrueOnline has three user accounts with default passwords, including two hardcoded service accounts: one with the username true and password true, and another with the username supervisor and password zyad1234. These accounts can be used to login to the web interface, exploit authenticated command injections, and change router settings for malicious purposes.
- Record
CVE-2017-18371- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-798
- Updated
- 2026-11-02
CVE List No score
The ZyXEL P660HN-T1A v2 TCLinux Fw #7.3.37.6 router distributed by TrueOnline has three user accounts with default passwords, including two hardcoded service accounts: one with the username true and password true, and another with the username supervisor and password zyad1234. These accounts can be used to login to the web interface, exploit authenticated command injections, and change router settings for malicious purposes.
- Record
CVE-2017-18371- Updated
- 2026-11-02
EUVDEUVD-2017-9487 No score
The ZyXEL P660HN-T1A v2 TCLinux Fw #7.3.37.6 router distributed by TrueOnline has three user accounts with default passwords, including two hardcoded service accounts: one with the username true and password true, and another with the username supervisor and password zyad1234. These accounts can be used to login to the web interface, exploit authenticated command injections, and change router settings for malicious purposes.
- Record
EUVD-2017-9487- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j9rw-cgp6-m49q
9.8
The ZyXEL P660HN-T1A v2 TCLinux Fw #7.3.37.6 router distributed by TrueOnline has three user...
The ZyXEL P660HN-T1A v2 TCLinux Fw #7.3.37.6 router distributed by TrueOnline has three user accounts with default passwords, including two hardcoded service accounts: one with the username true and password true, and another with the username supervisor and password zyad1234. These accounts can be used to login to the web interface, exploit authenticated command injections, and change router settings for malicious purposes.
- Record
GHSA-j9rw-cgp6-m49q- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-798
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Metasploit | TrueOnline / ZyXEL P660HN-T v2 Router Authenticated Command Injection | 2016-12-26 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, Metasploit, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2017-18371 is a critical vulnerability (CVSS 9.8) in Billion 5200w-t Firmware, published May 2, 2019. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 22.5%, the 97th percentile. No source names a fixed version.
References
seclists.org/fulldisclosure/2017/Jan/40
ssd-disclosure.com/index.php/archives/2910
unit42.paloaltonetworks.com/new-mirai-variant-targets-enterprise-wireless-presentation-display-systems
raw.githubusercontent.com/pedrib/PoC/master/advisories/zyxel_trueonline.txt
zyxel.com/support/announcement_unauthenticated.shtml
nvd.nist.gov/vuln/detail/CVE-2017-18371
github.com/advisories/GHSA-j9rw-cgp6-m49q