What’s Vulnerable › Vulnerabilities

CVE-1999-1087

• Severity: high (CVSS 7.5 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 6.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2002-03-09 · updated 2026-06-16

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

• Microsoft Internet Explorer 11: 4.0, 4.0.1, 4.0.1-sp1

References

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

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