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Fencer Vulns
high 8.8

CVE-2017-18374 json

The ZyXEL P660HN-T1A v1 TCLinux Fw $7.3.15.0 v001 / 3.40(ULM.0)b31 router distributed by TrueOnline has two user accounts with default pass…

published 2019-05-02 7 y ago modified 2026-06-17 4 mo ago also EUVD-2017-9490

cvss
8.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.5%
EPSS 5.5% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

The ZyXEL P660HN-T1A v1 TCLinux Fw $7.3.15.0 v001 / 3.40(ULM.0)b31 router distributed by TrueOnline has two user accounts with default passwords, including a hardcoded service account with the username true and password true. These accounts can be used to login to the web interface, exploit authenticated command injections and change router settings for malicious purposes.

Exploit prediction

5.50% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • seclists.org https://seclists.org/fulldisclosure/2017/Jan/40 referenced PoC, tagged "exploit" by a source, unverified
  • ssd-disclosure.com https://ssd-disclosure.com/index.php/archives/2910 referenced PoC, tagged "exploit" by a source, unverified
  • raw.githubusercontent.com https://raw.githubusercontent.com/pedrib/PoC/master/advisories/zyxel_trueonline.txt referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 9.0 AV:N/AC:L/Au:S/C:C/I:C/A:C

Classification

Weakness
  • CWE-798 Use of Hard-coded Credentials

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.