What is CVE-2021-43636?

CVE-2021-43636 is a critical-severity vulnerability in Totolink T10 V2, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2022-03-25.

How severe is CVE-2021-43636?

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

Buffer overflow in Totolink T10 V2

CVE-2021-43636

Two Buffer Overflow vulnerabilities exists in T10 V2_Firmware V4.1.8cu.5207_B20210320 in the http_request_parse function when processing host data in the HTTP request process.

Vulnerability class: Buffer Overflow

Published 2022-03-25 · 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: 0.011 (63.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Totolink T10 V2
Totolink T10 V2 Firmware — versions 4.1.8cu.5207_b20210320

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

note.youdao.com/s/918vCBNT (Broken Link)

Frequently asked questions

What is CVE-2021-43636?: CVE-2021-43636 is a critical-severity vulnerability in Totolink T10 V2, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2022-03-25.
How severe is CVE-2021-43636?: Critical severity. CVSS v3 base score is 9.8 out of 10.