What is CVE-2021-21740?

CVE-2021-21740 is a low-severity vulnerability in ZTE Zxhn H2640, classified under Improper Link Resolution Before File Access. CVSS score: 2.4/10. Published 2021-08-09.

How severe is CVE-2021-21740?

Low severity. CVSS v3 base score is 2.4 out of 10.

Vulnerability in ZTE Zxhn H2640

CVE-2021-21740

There is an information leak vulnerability in the digital media player (DMS) of ZTE's residential gateway product. The attacker could insert the USB disk with the symbolic link into the residential gateway, and access unauthorized directory information through the symbolic link, causing information leak.

Published 2021-08-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 2.4 (Low). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (35.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

ZTE Zxhn H2640
ZTE Zxhn H2640 Firmware — versions 10.0.0c6_ty
Zxhn H2640 — versions V10.0.0C6_TY

Weakness classification (CWE)

CWE-59 — Improper Link Resolution Before File Access

References

support.zte.com.cn/support/news/LoopholeInfoDetail.aspx (Vendor Advisory)

Frequently asked questions

What is CVE-2021-21740?: CVE-2021-21740 is a low-severity vulnerability in ZTE Zxhn H2640, classified under Improper Link Resolution Before File Access. CVSS score: 2.4/10. Published 2021-08-09.
How severe is CVE-2021-21740?: Low severity. CVSS v3 base score is 2.4 out of 10.