CVE-2021-43517

Name: CVE-2021-43517
Creator: NVD / NIST
Published: 2022-04-08T17:15:08.627+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.69%

Last modified Jun 17, 2026

CVE-2021-43517 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. FOSCAM Camera FI9805E with firmware V4.02.R12.00018510.10012.143900.00000 contains a backdoor that opens Telnet port when special command is sent on port 9530.. EPSS estimates a 1.69% chance of exploitation in the next 30 days.

Description

FOSCAM Camera FI9805E with firmware V4.02.R12.00018510.10012.143900.00000 contains a backdoor that opens Telnet port when special command is sent on port 9530.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

1.69%

74.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Foscam	Fi9805e Firmware	4.02.r12.00018510.10012.143900.00000

References

https://habr.com/ru/post/486856/Exploit, Third Party Advisory
https://habr.com/ru/post/486856/Exploit, Third Party Advisory

Timeline

Published: Apr 8, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43517?

FOSCAM Camera FI9805E with firmware V4.02.R12.00018510.10012.143900.00000 contains a backdoor that opens Telnet port when special command is sent on port 9530.

How severe is CVE-2021-43517?

CVE-2021-43517 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.69% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43517?

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-2021-43517?

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

Scan your code now

Source: NVD / NIST