What is CVE-2021-20847?

CVE-2021-20847 is a medium-severity vulnerability in Nttdocomo Wi-Fi Station Sh-52a, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-12-01.

How severe is CVE-2021-20847?

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

XSS in Nttdocomo Wi-Fi Station Sh-52a

CVE-2021-20847

Cross-site scripting vulnerability in Wi-Fi STATION SH-52A (38JP_1_11G, 38JP_1_11J, 38JP_1_11K, 38JP_1_11L, 38JP_1_26F, 38JP_1_26G, 38JP_1_26J, 38JP_2_03B, and 38JP_2_03C) allows a remote unauthenticated attacker to inject an arbitrary script via WebUI of the device.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-12-01 · 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: 0.008 (56.2th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.000

Affected products

Nttdocomo Wi-Fi Station Sh-52a
Nttdocomo Wi-Fi Station Sh-52a Firmware — versions 38jp_1_11g, 38jp_1_11j, 38jp_1_11k
Ntt Docomo, Inc. Wi-Fi Station Sh-52a — versions 38JP_1_11G, 38JP_1_11J, 38JP_1_11K, 38JP_1_11L, 38JP_1_26F, 38JP_1_26G, 38JP_1_26J, 38JP_2_03B, and 38JP_2_03C

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.nttdocomo.co.jp/support/product_update/sh52a/index.html (Third Party Advisory)
jvn.jp/en/jp/JVN19482703/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-20847?: CVE-2021-20847 is a medium-severity vulnerability in Nttdocomo Wi-Fi Station Sh-52a, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-12-01.
How severe is CVE-2021-20847?: Medium severity. CVSS v3 base score is 6.1 out of 10.