What is CVE-2021-20155?

CVE-2021-20155 is a critical-severity vulnerability in Trendnet Tew-827dru, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2021-12-30.

How severe is CVE-2021-20155?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2021-20155 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Trendnet Tew-827dru

CVE-2021-20155

Trendnet AC2600 TEW-827DRU version 2.08B01 makes use of hardcoded credentials. It is possible to backup and restore device configurations via the management web interface. These devices are encrypted using a hardcoded password of "12345678".

Published 2021-12-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.019 (78.9th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

Trendnet Tew-827dru — versions 2.0
Trendnet Tew-827dru Firmware — versions 2.08b01
Trendnet Ac2600 Tew-827dru — versions 2.08B01

Weakness classification (CWE)

CWE-798 — Use of Hard-coded Credentials

Public proof-of-concept exploits

References

www.tenable.com/security/research/tra-2021-54 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-20155?: CVE-2021-20155 is a critical-severity vulnerability in Trendnet Tew-827dru, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2021-12-30.
How severe is CVE-2021-20155?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-20155 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.