What is CVE-2021-27169?

CVE-2021-27169 is a critical-severity vulnerability in Fiberhome An5506-04-Fa, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2021-02-10.

How severe is CVE-2021-27169?

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

Vulnerability in Fiberhome An5506-04-Fa

CVE-2021-27169

An issue was discovered on FiberHome AN5506-04-FA devices with firmware RP2631. There is a gepon password for the gepon account.

Published 2021-02-10 · 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: 0.198 (97.3th percentile), scored 2026-10-01.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.198 · newest: 0.198 · change: 0.000

Affected products

Fiberhome An5506-04-Fa
Fiberhome An5506-04-Fa Firmware — versions rp2631

Weakness classification (CWE)

CWE-798 — Use of Hard-coded Credentials

References

pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-27169?: CVE-2021-27169 is a critical-severity vulnerability in Fiberhome An5506-04-Fa, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2021-02-10.
How severe is CVE-2021-27169?: Critical severity. CVSS v3 base score is 9.8 out of 10.