CVE-1999-1591

critical

Description

Microsoft Internet Information Services (IIS) server 4.0 SP4, without certain hotfixes released for SP4, does not require authentication credentials under certain conditions, which allows remote attackers to bypass authentication requirements, as demonstrated by connecting via Microsoft Visual InterDev 6.0.

References

http://www.securityfocus.com/bid/190

http://archives.neohapsis.com/archives/ntbugtraq/1998-1999/msg00277.html

http://archives.neohapsis.com/archives/ntbugtraq/1998-1999/msg00276.html

Details

Source: Mitre, NVD

Published: 1999-12-31

Updated: 2026-06-16

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.13492