CVE-2021-21403: In github.com/kongchuanhujiao/server before version 1.3.21 there is an authentication Bypass by Primary Weakne

Q: How do I fix CVE-2021-21403?

kongchuanhujiao: upgrade to 1.3.21. Exact commands for each OS are on this page.

Q: Is CVE-2021-21403 being exploited?

CVE-2021-21403 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-2021-21403 affect?

CVE-2021-21403 affects kongchuanhujiao. Severity is high (CVSS 7.5). In github.com/kongchuanhujiao/server before version 1.3.21 there is an authentication Bypass by Primary Weakness vulnerability. All users are impacted. This is fixed in version 1.3.21.

Q: How urgent is CVE-2021-21403?

Priority 49/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2021-21403 is a high-severity flaw (CVSS 7.5) affecting kongchuanhujiao. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In github.com/kongchuanhujiao/server before version 1.3.21 there is an authentication Bypass by Primary Weakness vulnerability. All users are impacted. This is fixed in version 1.3.21.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.4% (top 28%)
CISA exploited list	No
Weakness	CWE-305, CWE-287
Published	2021-03-26
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: kongchuanhujiao project

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

Am I affected?

Timeline

2021-03-26 18:15 UTCPublished CVE record published
2026-06-17 03:35 UTCUpdated Record last modified

kongchuanhujiao project kongchuanhujiao UPGRADE

Affected: < 1.3.21

Fixed in: 1.3.21

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy kongchuanhujiao || rpm -q kongchuanhujiao || kongchuanhujiao --version

2. UPGRADE to 1.3.21 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kongchuanhujiao

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kongchuanhujiao

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-2021-21403?

kongchuanhujiao: upgrade to 1.3.21. Exact commands for each OS are on this page.

Is CVE-2021-21403 being exploited?

CVE-2021-21403 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-2021-21403 affect?

CVE-2021-21403 affects kongchuanhujiao. Severity is high (CVSS 7.5). In github.com/kongchuanhujiao/server before version 1.3.21 there is an authentication Bypass by Primary Weakness vulnerability. All users are impacted. This is fixed in version 1.3.21.

How urgent is CVE-2021-21403?

Priority 49/100. High severity; Remotely exploitable, no login, no user action

Software pages

GitHub vulnerabilities

References

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