CVE-1999-1087

Name: CVE-1999-1087
Creator: NVD / NIST
Published: 1999-12-31T05:00:00+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 6.28%

Last modified Jun 16, 2026

CVE-1999-1087 is a vulnerability of currently unknown severity. Internet Explorer 4 treats a 32-bit number ("dotless IP address") in the a URL as the hostname instead of an IP address, which causes IE to apply Local Intranet Zone settings to the resulting web page, allowing remote malicious web servers to conduct unauthorized activities by using URLs that contain the dotless IP address for their server.. EPSS estimates a 6.28% chance of exploitation in the next 30 days.

Description

Internet Explorer 4 treats a 32-bit number ("dotless IP address") in the a URL as the hostname instead of an IP address, which causes IE to apply Local Intranet Zone settings to the resulting web page, allowing remote malicious web servers to conduct unauthorized activities by using URLs that contain the dotless IP address for their server.

Metrics

EPSS Probability

6.28%

92.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Microsoft	Internet Explorer	4.0
Microsoft	Internet Explorer	4.0.1

References

Timeline

Published: Dec 31, 1999
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-1999-1087?

How severe is CVE-1999-1087?

Severity scoring for CVE-1999-1087 is pending analysis. The EPSS model estimates a 6.28% probability of exploitation in the next 30 days.

How do I fix CVE-1999-1087?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-1999-1087?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST