VDB-14443 · CVE-1999-0391 · BID 233

Microsoft Windows up to 2000 SMB Authentication improper authentication

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Microsoft Windows 95/98/NT 3.51/NT 4.0/2000. Affected by this vulnerability is an unknown functionality of the component SMB Authentication. This manipulation causes improper authentication. This vulnerability appears as CVE-1999-0391. The attack may be initiated remotely. In addition, an exploit is available. This vulnerability is considered historic because of its background and reception. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in Microsoft Windows 95/98/NT 3.51/NT 4.0/2000 (Operating System). It has been declared as critical. Affected by this vulnerability is some unknown functionality of the component SMB Authentication. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

The cryptographic challenge of SMB authentication in Windows 95 and Windows 98 can be reused, allowing an attacker to replay the response and impersonate a user.

The issue has been introduced in 08/24/1995. The weakness was presented 01/05/1999. This vulnerability is known as CVE-1999-0391. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are unknown but a public exploit is available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/26/2025). Due to its background and reception, this vulnerability has a historic impact.

It is declared as highly functional. The vulnerability was handled as a non-public zero-day exploit for at least 1230 days. During that time the estimated underground price was around $5k-$25k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 70011 (Windows NT LanMan Hash Replay with Modified SMB Client Vulnerability).

Applying a patch is able to eliminate this problem.

The vulnerability is also documented in the databases at SecurityFocus (BID 233†) and Vulnerability Center (SBV-3779†). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Highly functional

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Timelineinfo

08/24/1995 🔍
04/08/1997 +592 days 🔍
01/05/1999 +637 days 🔍
01/05/1999 +0 days 🔍
01/05/1999 +0 days 🔍
02/16/2004 +1868 days 🔍
06/20/2014 +3777 days 🔍
10/26/2025 +4145 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Status: Confirmed

CVE: CVE-1999-0391 (🔍)
GCVE (CVE): GCVE-0-1999-0391
GCVE (VulDB): GCVE-100-14443
SecurityFocus: 233
Vulnerability Center: 3779 - Windows NT SMB Authentication Compromise, Medium

scip Labs: https://www.scip.ch/en/?labs.20140213

Entryinfo

Created: 06/20/2014 12:46
Updated: 10/26/2025 01:23
Changes: 06/20/2014 12:46 (58), 05/03/2019 06:58 (1), 06/23/2021 09:14 (3), 10/26/2025 01:23 (18)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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