What is CVE-2021-43662?

CVE-2021-43662 is a medium-severity vulnerability in Totolink A720r, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 6.5/10. Published 2022-03-31.

How severe is CVE-2021-43662?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Resource exhaustion in Totolink A720r

CVE-2021-43662

totolink EX300_v2, ver V4.0.3c.140_B20210429 and A720R ,ver V4.1.5cu.470_B20200911 have an issue which causes uncontrolled resource consumption.

Published 2022-03-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (43.6th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Totolink A720r
Totolink A720r Firmware — versions 4.1.5cu.470_b20200911
Totolink Ex300 V2
Totolink Ex300 V2 Firmware — versions 4.0.3c.140_b20210429

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

github.com/chibataiki/iot-vuls/blob/main/totolink/dos.md (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43662?: CVE-2021-43662 is a medium-severity vulnerability in Totolink A720r, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 6.5/10. Published 2022-03-31.
How severe is CVE-2021-43662?: Medium severity. CVSS v3 base score is 6.5 out of 10.