CVE-1999-1591

High CVSS 7.5

Published 1999-12-31 · last changed 2026-06-16

The fix

We hold no Microsoft remediation data for CVE-1999-1591, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

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.

Sources

NVD record for CVE-1999-1591

CVSS vector: AV:N/AC:L/Au:N/C:P/I:P/A:P