CVE-2009-1535: Microsoft Internet Information Services

High severity, CVSS 7.5. EPSS: 98.1% chance of exploitation in the next 30 days.

The WebDAV extension in Microsoft Internet Information Services (IIS) 5.1 and 6.0 allows remote attackers to bypass URI-based protection mechanisms, and list folders or read, create, or modify files, via a %c0%af (Unicode / character) at an arbitrary position in the URI, as demonstrated by inserting %c0%af into a "/protected/" initial pathname component to bypass the password protection on the protected\ folder, aka "IIS 5.1 and 6.0 WebDAV Authentication Bypass Vulnerability," a different vulnerability than CVE-2009-1122.

Affected products

• Microsoft Internet Information Services: version 5.1 only; version 6.0 only

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