Microsoft Windows NT 4.0 Local Security Authority Subsystem LsaLookupSids input validation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.2	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in Microsoft Windows NT 4.0. The impacted element is the function LsaLookupSids of the component Local Security Authority Subsystem. The manipulation results in input validation. This vulnerability is identified as CVE-1999-0995. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Microsoft Windows NT 4.0 (Operating System). Affected is the function LsaLookupSids of the component Local Security Authority Subsystem. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. CVE summarizes:

Windows NT Local Security Authority (LSA) allows remote attackers to cause a denial of service via malformed arguments to the LsaLookupSids function which looks up the SID, aka "Malformed Security Identifier Request."

The weakness was released 12/16/1999 with Network Associates as MS99-057 as confirmed bulletin (Technet). The advisory is available at microsoft.com. This vulnerability is traded as CVE-1999-0995. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit.

Upgrading eliminates this vulnerability. Applying the patch MS99-057 is able to eliminate this problem. The bugfix is ready for download at microsoft.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at X-Force (3759), SecurityFocus (BID 875†) and Vulnerability Center (SBV-3128†). Entry connected to this vulnerability is available at VDB-15065. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• NT 4.0

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

CPE 2.3info

• 🔍
• 🔍
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CPE 2.2info

• 🔍
• 🔍
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CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Patch: MS99-057
ISS Proventia IPS: 🔍

Timelineinfo

12/16/1999 🔍
12/16/1999 +0 days 🔍
12/16/1999 +0 days 🔍
12/16/1999 +0 days 🔍
12/10/2003 +1455 days 🔍
06/22/2014 +3847 days 🔍
04/19/2026 +4319 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: MS99-057
Organization: Network Associates
Status: Confirmed

CVE: CVE-1999-0995 (🔍)
GCVE (CVE): GCVE-0-1999-0995
GCVE (VulDB): GCVE-100-15066
X-Force: 3759
SecurityFocus: 875 - NT LsaLookupSids() DoS Vulnerability
Vulnerability Center: 3128 - [MS99-057] DoS in Windows NT via a Malformed Security Identifier Request, Medium

See also: 🔍

Entryinfo

Created: 06/22/2014 16:02
Updated: 04/19/2026 23:25
Changes: 06/22/2014 16:02 (45), 05/17/2019 18:54 (21), 04/19/2026 23:25 (16)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion

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