CVE-2009-1535

Exp

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.

Published: 2009-06-10 Last update: 2026-04-23 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-1535 is rated High Exploit Risk (81.3/100): CVSS High severity, with high exploitation likelihood (EPSS 91.83%, 100th percentile). 2 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.45% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2009-1535

EDB-ID Source Kind Published Link
8806 exploit_db edb 2009-05-26 Exploit-DB ↗
8704 exploit_db edb 2009-05-15 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2009-1535

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-04 90.38% 91.83% +1.45%
2 2026-03-01 91.83% 90.38% -1.45%
3 2026-02-04 — 91.83% —

Full EPSS history (52 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-1535

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2009-1535

Affected software / configurations for CVE-2009-1535

Vendor Product Version Raw CPE
microsoft internet_information_services 5.1 cpe:2.3:a:microsoft:internet_information_services:5.1:*:*:*:*:*:*:*
microsoft internet_information_services 6.0 cpe:2.3:a:microsoft:internet_information_services:6.0:*:*:*:*:*:*:*

References for CVE-2009-1535

URL Tags
http://archives.neohapsis.com/archives/fulldisclosure/2009-05/0135.html Broken Link
http://archives.neohapsis.com/archives/fulldisclosure/2009-05/0139.html Broken Link
http://archives.neohapsis.com/archives/fulldisclosure/2009-05/0144.html Broken Link
http://archives.neohapsis.com/archives/fulldisclosure/2009-05/att-0135/IIS_Advisory.pdf Broken Link
http://blog.zoller.lu/2009/05/iis-6-webdac-auth-bypass-and-data.html Third Party Advisory
http://isc.sans.org/diary.html?n&storyid=6397 Third Party Advisory
http://view.samurajdata.se/psview.php?id=023287d6&page=1 Broken Link
http://www.attrition.org/pipermail/vim/2009-June/002192.html Third Party Advisory
http://www.us-cert.gov/cas/techalerts/TA09-160A.html Third Party Advisory US Government Resource
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-020 Patch Vendor Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6029 Third Party Advisory
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