VULNERABILITY INTELLIGENCE
CVE-1999-1591
CVSS score7.5 HIGH
EPSS probability11.27%
CISA KEVNot currently listed
Published1999-12-31
Last modified2026-06-16
CVSS vectorAV:N/AC:L/Au:N/C:P/I:P/A:P
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.