What is CVE-2021-43661?

CVE-2021-43661 is a medium-severity vulnerability in Totolink Ex300 V2, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2022-03-31.

How severe is CVE-2021-43661?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Totolink Ex300 V2

CVE-2021-43661

totolink EX300_v2 V4.0.3c.140_B20210429 was discovered to contain a reflected cross-site scripting (XSS) vulnerability via the component /home.asp.

Vulnerability class: XSS (Cross-Site Scripting)

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

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (48.7th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Totolink Ex300 V2
Totolink Ex300 V2 Firmware — versions 4.0.3c.140_b20210429

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

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

Frequently asked questions

What is CVE-2021-43661?: CVE-2021-43661 is a medium-severity vulnerability in Totolink Ex300 V2, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2022-03-31.
How severe is CVE-2021-43661?: Medium severity. CVSS v3 base score is 6.1 out of 10.