# CVE-1999-0225: Microsoft Windows NT denial of service in SMB logon request

Source: https://junglewise.ai/threats/cve-1999-0225-microsoft-windows-nt-denial-of-service-in-smb-logon-request  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 1998-02-14. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-1999-0225 · Severity: medium · CVSS 5 · Published 1998-02-14

A vulnerability in Windows NT 4.0 allows an attacker to remotely crash the operating system. By sending a specially crafted login request over the network, an attacker can cause the system to stop responding or reboot. This results in a denial of service, disrupting business operations and making the server unavailable to legitimate users.

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

## Quick answers

**Is CVE-1999-0225 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-1999-0225 being exploited in the wild.

**How severe is CVE-1999-0225?** Medium severity, with a CVSS score of 5, published 14 February 1998.

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

**Is there a fix for CVE-1999-0225?** 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-1999-0225 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-1999-0225?** Check whether you run Microsoft Windows Nt. 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

A denial of service vulnerability exists in the SMB (Server Message Block) implementation of Windows NT 4.0. The flaw is triggered when the system processes a malformed SMB logon request where the actual payload size differs from the size specified in the packet header. A remote, unauthenticated attacker can exploit this by sending a crafted packet to the target system, leading to a system crash or hang. Microsoft addressed this issue in Knowledge Base article 180963.

## Affected products

- Microsoft Windows NT 4.0

## Timeline

- 1998-02-14: advisory: NVD published date

## References

- [http://www.microsoft.com/technet/support/kb.asp?ID=180963](http://www.microsoft.com/technet/support/kb.asp?ID=180963)
- [http://www.nai.com/nai_labs/asp_set/advisory/25_windows_nt_dos_adv.asp](http://www.nai.com/nai_labs/asp_set/advisory/25_windows_nt_dos_adv.asp)

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