CVE-2009-1122: Microsoft Internet Information Services

High severity, CVSS 7.5. EPSS: 98.4% chance of exploitation in the next 30 days.

The WebDAV extension in Microsoft Internet Information Services (IIS) 5.0 on Windows 2000 SP4 does not properly decode URLs, which allows remote attackers to bypass authentication, and possibly read or create files, via a crafted HTTP request, aka "IIS 5.0 WebDAV Authentication Bypass Vulnerability," a different vulnerability than CVE-2009-1535.

Affected products

• Microsoft Internet Information Services: version 5.0 only

Published 2009-06-10. Last modified 2026-06-16.