CVE-2021-27173

Name: CVE-2021-27173
Creator: NVD / NIST
Published: 2021-02-10T19:15:15.183+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 12.67%

Last modified Jun 17, 2026

CVE-2021-27173 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered on FiberHome HG6245D devices through RP2613. There is a telnet?enable=0&key=calculated(BR0_MAC) backdoor API, without authentication, provided by the HTTP server. EPSS estimates a 12.67% chance of exploitation in the next 30 days.

Description

An issue was discovered on FiberHome HG6245D devices through RP2613. There is a telnet?enable=0&key=calculated(BR0_MAC) backdoor API, without authentication, provided by the HTTP server. This will remove firewall rules and allow an attacker to reach the telnet server (used for the CLI).

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

12.67%

95.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Fiberhome	Hg6245d Firmware	<= rp2613

References

https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#httpd-infoleakExploit, Third Party Advisory
https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#httpd-infoleakExploit, Third Party Advisory

Timeline

Published: Feb 10, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-27173?

How severe is CVE-2021-27173?

CVE-2021-27173 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 12.67% probability of exploitation in the next 30 days.

How do I fix CVE-2021-27173?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-27173?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST