VDB-14343 · CVE-1999-0549 · XFDB 5

Microsoft Windows NT Login improper authentication

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.
6.9	$0-$5k	1.23

Summaryinfo

A vulnerability was found in Microsoft Windows NT. It has been rated as problematic. Affected is an unknown function of the component Login Handler. Performing a manipulation results in improper authentication. This vulnerability was named CVE-1999-0549. The attack needs to be approached locally. In addition, an exploit is available. Due to its background and reception, this vulnerability has an historic impact. It is recommended to change the configuration settings.

Detailsinfo

A vulnerability was found in Microsoft Windows NT (Operating System). It has been classified as critical. This affects an unknown function of the component Login Handler. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Windows NT automatically logs in an administrator upon rebooting.

The weakness was presented 01/01/1999. This vulnerability is uniquely identified as CVE-1999-0549. Attacking locally is a requirement. The successful exploitation requires a 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 04/18/2026). Due to its background and reception, this vulnerability has a historic impact.

It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $5k-$25k.

It is possible to mitigate the problem by applying the configuration setting .

The vulnerability is also documented in the databases at X-Force (5) and Vulnerability Center (SBV-625†). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Operating System

Vendor

Microsoft

Name

Windows

Version

License

commercial

Website

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

CPE 2.3info

🔍

CPE 2.2info

🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 6.9

VulDB Base Score: 7.8
VulDB Temp Score: 6.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

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

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Access: Public
Status: Proof-of-Concept

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: Config
Status: 🔍

0-Day Time: 🔍

Timelineinfo

01/01/1999 🔍
01/01/1999 +0 days 🔍
01/01/1999 +0 days 🔍
01/01/2003 +1461 days 🔍
06/19/2014 +4187 days 🔍
04/18/2026 +4320 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Status: Not defined

CVE: CVE-1999-0549 (🔍)
GCVE (CVE): GCVE-0-1999-0549
GCVE (VulDB): GCVE-100-14343
X-Force: 5
Vulnerability Center: 625 - Windows NT/2000 Allows Logging-In Automatically, Critical

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 06/20/2014 00:49
Updated: 04/18/2026 00:20
Changes: 06/20/2014 00:49 (56), 04/18/2026 00:20 (19)
Complete: 🔍
Cache ID: 216::103