CVE-1999-1087 — 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

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HIGH

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

Published Mar 9, 2002

7.5

HIGH

CVSS 2.0

EPSS 6.40%

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.

Affected products

Remediation

No remediation recorded yet.

Metrics

6.40% 0.06401

Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.

EPSS probability 0.06401

Score over time

2022–2026

EPSS v2
EPSS v3
EPSS v4
EPSS v5

Percentile over time

EPSS v2
EPSS v3
EPSS v4
EPSS v5

Table of values (14 key points)

Flat stretches are collapsed; showing up to 120 newest points.

Date	Score	Percentile	Model
Oct 3, 2026	6.40% (0.06401)	93.47th	v5 (v2026.06.15)
Jun 15, 2026	6.28% (0.06281)	92.66th	v5 (v2026.06.15)
Jun 14, 2026	9.02% (0.09023)	92.84th	v4 (v2025.03.14)
May 11, 2026	11.77% (0.11771)	93.76th	v4 (v2025.03.14)
Apr 14, 2026	9.02% (0.09023)	92.63th	v4 (v2025.03.14)
Mar 17, 2025	10.20% (0.10203)	92.56th	v4 (v2025.03.14)
Dec 12, 2024	0.39% (0.00392)	74.18th	v3 (v2023.03.01)
Feb 15, 2024	0.39% (0.00392)	72.67th	v3 (v2023.03.01)
Feb 7, 2024	0.39% (0.00392)	70.66th	v3 (v2023.03.01)
Jul 18, 2023	0.61% (0.00610)	75.83th	v3 (v2023.03.01)
Mar 7, 2023	0.72% (0.00718)	77.53th	v3 (v2023.03.01)
Mar 6, 2023	6.12% (0.06118)	90.60th	v2 (v2022.01.01)
Apr 1, 2022	6.12% (0.06118)	89.73th	v2 (v2022.01.01)
Feb 4, 2022	6.12% (0.06118)	77.57th	v2 (v2022.01.01)

Weaknesses (0)

No CWE recorded.

References (5)

http://support.microsoft.com/support/kb/articles/q168/6/17.asp
vendor-advisoryx_refsource_MSKBPatchVendor Advisory
http://www.microsoft.com/Windows/Ie/security/dotless.asp
x_refsource_CONFIRM
http://www.osvdb.org/7828
vdb-entryx_refsource_OSVDB
https://docs.microsoft.com/en-us/security-updates/securitybulletins/1998/ms98-016
vendor-advisoryx_refsource_MS
https://exchange.xforce.ibmcloud.com/vulnerabilities/2209
vdb-entryx_refsource_XF

Link	Providers	Tags
http://support.microsoft.com/support/kb/articles/q168/6/17.asp		vendor-advisoryx_refsource_MSKBPatchVendor Advisory
http://www.microsoft.com/Windows/Ie/security/dotless.asp		x_refsource_CONFIRM
http://www.osvdb.org/7828		vdb-entryx_refsource_OSVDB
https://docs.microsoft.com/en-us/security-updates/securitybulletins/1998/ms98-016		vendor-advisoryx_refsource_MS
https://exchange.xforce.ibmcloud.com/vulnerabilities/2209		vdb-entryx_refsource_XF

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED

Assigner mitre

Published Mar 9, 2002

Updated Aug 1, 2024

Reserved Aug 31, 2001

Link CVE-1999-1087

CISA Vulnrichment

Updated n/a

NVD

Status Modified

Modified Jun 16, 2026

Link CVE-1999-1087

Red Hat

Severity n/a

Public date n/a

Links CVE-1999-1087