CVE-2021-20749: Cross-site scripting vulnerability in Fudousan plugin ver5.7.0 and earlier, Fudousan Plugin Pro Single-User Ty

Q: How do I fix CVE-2021-20749?

fudousan plugin: upgrade to newer than 5.7.0; fudousan plugin pro multi-user: upgrade to newer than 5.7.0; fudousan plugin pro single-user: upgrade to newer than 5.7.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-20749 being exploited?

CVE-2021-20749 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-20749 affect?

CVE-2021-20749 affects fudousan plugin, fudousan plugin pro multi-user, fudousan plugin pro single-user. Severity is medium (CVSS 5.4). Cross-site scripting vulnerability in Fudousan plugin ver5.7.0 and earlier, Fudousan Plugin Pro Single-User Type ver5.7.0 and earlier, and Fudousan Plugin Pro Multi-User Type ver5.7.0 and earlier allows a remote authenticated attacker to in

Q: How urgent is CVE-2021-20749?

Priority 35/100. No elevated risk signals yet.

Routine

MEDIUM 5.4UPGRADEUPGRADEUPGRADE

CVE-2021-20749 is a medium-severity flaw (CVSS 5.4) affecting fudousan plugin, fudousan plugin pro multi-user, fudousan plugin pro single-user. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross-site scripting vulnerability in Fudousan plugin ver5.7.0 and earlier, Fudousan Plugin Pro Single-User Type ver5.7.0 and earlier, and Fudousan Plugin Pro Multi-User Type ver5.7.0 and earlier allows a remote authenticated attacker to inject an arbitrary script via unspecified vectors.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	1.0% (top 38%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-06-28
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2021-06-28 01:15 UTCPublished CVE record published
2026-06-17 03:34 UTCUpdated Record last modified

nendeb fudousan plugin UPGRADE

Affected: <= 5.7.0

Fixed in: newer than 5.7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy fudousan-plugin || rpm -q fudousan-plugin || fudousan-plugin --version

2. UPGRADE to newer than 5.7.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fudousan-plugin

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fudousan-plugin

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

nendeb fudousan plugin pro multi-user UPGRADE

Affected: <= 5.7.0

Fixed in: newer than 5.7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy fudousan-plugin-pro-multi-user || rpm -q fudousan-plugin-pro-multi-user || fudousan-plugin-pro-multi-user --version

2. UPGRADE to newer than 5.7.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fudousan-plugin-pro-multi-user

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fudousan-plugin-pro-multi-user

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

nendeb fudousan plugin pro single-user UPGRADE

Affected: <= 5.7.0

Fixed in: newer than 5.7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy fudousan-plugin-pro-single-user || rpm -q fudousan-plugin-pro-single-user || fudousan-plugin-pro-single-user --version

2. UPGRADE to newer than 5.7.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fudousan-plugin-pro-single-user

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fudousan-plugin-pro-single-user

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2021-20749?

fudousan plugin: upgrade to newer than 5.7.0; fudousan plugin pro multi-user: upgrade to newer than 5.7.0; fudousan plugin pro single-user: upgrade to newer than 5.7.0. Exact commands for each OS are on this page.

Is CVE-2021-20749 being exploited?

CVE-2021-20749 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-2021-20749 affect?

CVE-2021-20749 affects fudousan plugin, fudousan plugin pro multi-user, fudousan plugin pro single-user. Severity is medium (CVSS 5.4). Cross-site scripting vulnerability in Fudousan plugin ver5.7.0 and earlier, Fudousan Plugin Pro Single-User Type ver5.7.0 and earlier, and Fudousan Plugin Pro Multi-User Type ver5.7.0 and earlier allows a remote authenticated attacker to in

How urgent is CVE-2021-20749?

Priority 35/100. No elevated risk signals yet.

References

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