# CVE-1999-0275: Microsoft Windows NT DNS server denial of service via port 53 flooding

Source: https://junglewise.ai/threats/cve-1999-0275-microsoft-windows-nt-dns-server-denial-of-service-via-port-53  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 1997-06-10. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-1999-0275 · Severity: medium · CVSS 5 · Published 1997-06-10

A vulnerability in the Windows NT DNS service allows an attacker to crash the server by sending a large volume of data to the network port used for domain name resolution. This can result in a denial-of-service condition, preventing users and systems from resolving website names or internal network addresses. This disruption can halt business operations that rely on network connectivity and name resolution.

Technologies: [Microsoft Windows Nt](https://junglewise.ai/threats/technologies/windows-nt). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-1999-0275 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-1999-0275 being exploited in the wild.

**How severe is CVE-1999-0275?** Medium severity, with a CVSS score of 5, published 10 June 1997.

**Which products and versions are affected?** Microsoft Windows NT DNS Server Windows NT 4.0 and earlier.

**Is there a fix for CVE-1999-0275?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-1999-0275 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-1999-0275?** Check whether you run Microsoft Windows NT DNS Server or Microsoft Windows Nt at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The Windows NT DNS server is vulnerable to a denial of service (DoS) attack. The vulnerability is triggered by sending a large volume of characters to UDP or TCP port 53, which the DNS service fails to handle correctly. An unauthenticated remote attacker can exploit this by flooding the port with malformed or oversized requests, leading to a service crash or hang. This prevents the server from responding to legitimate DNS queries. The issue is categorized as a resource exhaustion or improper input validation flaw within the DNS service component.

## Affected products

- Microsoft Windows NT DNS Server Windows NT 4.0 and earlier

## Timeline

- 1997-06-10: disclosed: Initial publication date

## References

- [https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0275](https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0275)

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