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, 38

Routine

MEDIUM 6.1MITIGATE

CVE-2021-20847 is a medium-severity flaw (CVSS 6.1) affecting wi-fi station sh-52a firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 42%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-12-01
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: nttdocomo

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-12-01 03:15 UTCPublished CVE record published
2026-06-17 03:34 UTCUpdated Record last modified

nttdocomo wi-fi station sh-52a firmware MITIGATE

Affected: 38jp_1_11g · 38jp_1_11j · 38jp_1_11k · 38jp_1_11l · 38jp_1_26f · 38jp_1_26g · 38jp_1_26j · 38jp_2_03b

Fixed in: no fixed release known

Safe to downgrade to: a release before 38jp_1_11g

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-20847?

wi-fi station sh-52a firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-20847 being exploited?

CVE-2021-20847 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-20847 affect?

CVE-2021-20847 affects wi-fi station sh-52a firmware. Severity is medium (CVSS 6.1). 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 scri

How urgent is CVE-2021-20847?

Priority 36/100. No elevated risk signals yet.

Software pages

Wi-Fi vulnerabilities

References

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