HOMEVULNERABILITIESCVE-2021-4248
CRITICAL

CVE-2021-4248

CWE-330Published: December 18, 2022· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

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. The identifier of this vulnerability is VDB-216188.

NVD Source

Technical Analysis

CVE-2021-4248 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

kapetan_dns_project1 product(s)
kapetan dns
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/kapetan/dns/commit/cf7105aa2aae90d6656088fe5a8ee1d5730773b6
PATCHhttps://github.com/kapetan/dns/pull/88
PATCHhttps://github.com/kapetan/dns/commit/cf7105aa2aae90d6656088fe5a8ee1d5730773b6
PATCHhttps://github.com/kapetan/dns/pull/88
ADVISORYhttps://github.com/kapetan/dns/releases/tag/v7.0.0
ADVISORYhttps://vuldb.com/?id.216188
ADVISORYhttps://github.com/kapetan/dns/releases/tag/v7.0.0
ADVISORYhttps://vuldb.com/?id.216188

All References (8)

→
https://github.com/kapetan/dns/commit/cf7105aa2aae90d6656088fe5a8ee1d5730773b6Patch · Third Party Advisory
→
https://github.com/kapetan/dns/pull/88Patch · Third Party Advisory
→
https://github.com/kapetan/dns/releases/tag/v7.0.0Release Notes · Third Party Advisory
→
https://vuldb.com/?id.216188Permissions Required · Third Party Advisory
→
https://github.com/kapetan/dns/commit/cf7105aa2aae90d6656088fe5a8ee1d5730773b6Patch · Third Party Advisory
→
https://github.com/kapetan/dns/pull/88Patch · Third Party Advisory
→
https://github.com/kapetan/dns/releases/tag/v7.0.0Release Notes · Third Party Advisory
→
https://vuldb.com/?id.216188Permissions Required · Third Party Advisory

Quick Facts

CVE IDCVE-2021-4248
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-330
CISA KEVNo
Affected1 vendor(s)
PublishedDec 18, 2022

Related CVEs (CWE-330)

CVE-2024-25943
9.8
CVE-2022-22922
9.8
CVE-2024-21495
9.8
CVE-2023-46740
9.8
CVE-2024-36389
9.8
CVE-2021-36166
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-4248 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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