What is CVE-2021-43517?

CVE-2021-43517 is a critical-severity vulnerability in Foscam Fi9805e. CVSS score: 9.8/10. Published 2022-04-08.

How severe is CVE-2021-43517?

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

Vulnerability in Foscam Fi9805e

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.

Published 2022-04-08 · 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: 0.017 (76.5th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 76.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000

Affected products

Foscam Fi9805e
Foscam Fi9805e Firmware — versions 4.02.r12.00018510.10012.143900.00000

References

habr.com/ru/post/486856/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43517?: CVE-2021-43517 is a critical-severity vulnerability in Foscam Fi9805e. CVSS score: 9.8/10. Published 2022-04-08.
How severe is CVE-2021-43517?: Critical severity. CVSS v3 base score is 9.8 out of 10.