CVE-2021-4248: A vulnerability was found in kapetan dns up to 6.1.0

Q: How do I fix CVE-2021-4248?

kapetan dns: upgrade to 7.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-4248 being exploited?

CVE-2021-4248 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-2021-4248 affect?

CVE-2021-4248 affects kapetan dns. Severity is medium (CVSS 5.6). A vulnerability was found in kapetan dns up to 6.1.0. It has been rated as problematic. Affected by this issue is some unknown functionality of the file DNS/Protocol/Request.cs. The manipulation leads to insufficient entropy in prng. The at

Q: How urgent is CVE-2021-4248?

Priority 39/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.6REMOTEUPGRADE

CVE-2021-4248 is a medium-severity flaw (CVSS 5.6) affecting kapetan dns. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was found in kapetan dns up to 6.1.0. It has been rated as problematic. Affected by this issue is some unknown functionality of the file DNS/Protocol/Request.cs. The manipulation leads to insufficient entropy in prng. The attack may be launched remotely. Upgrading to version 7.0.0 is able to address this issue. The name of the patch is cf7105aa2aae90d6656088fe5a8ee1d5730773b6. It is recommended to upgrade the affected component. T

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.6 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-330
Published	2022-12-18
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: kapetan dns project

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

Am I affected?

Timeline

2022-12-18 11:15 UTCPublished CVE record published
2026-06-17 04:19 UTCUpdated Record last modified

kapetan dns project kapetan dns UPGRADE

Affected: < 7.0.0

Fixed in: 7.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy kapetan-dns || rpm -q kapetan-dns || kapetan-dns --version

2. UPGRADE to 7.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kapetan-dns

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kapetan-dns

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-2021-4248?

kapetan dns: upgrade to 7.0.0. Exact commands for each OS are on this page.

Is CVE-2021-4248 being exploited?

CVE-2021-4248 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-2021-4248 affect?

CVE-2021-4248 affects kapetan dns. Severity is medium (CVSS 5.6). A vulnerability was found in kapetan dns up to 6.1.0. It has been rated as problematic. Affected by this issue is some unknown functionality of the file DNS/Protocol/Request.cs. The manipulation leads to insufficient entropy in prng. The at

How urgent is CVE-2021-4248?

Priority 39/100. Remotely exploitable, no login, no user action

References

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