How severe is CVE-2009-1535?

No CVSS score has been assigned to CVE-2009-1535 yet. Review the advisory details and affected package list to assess your exposure.

Which products are affected by CVE-2009-1535?

CVE-2009-1535 affects the following products: microsoft internet information services.

How do I patch CVE-2009-1535?

No patch has shipped for CVE-2009-1535 yet — track the microsoft internet information services advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2009-1535 across my infrastructure?

Inventory every microsoft internet information services deployment and check each version against the affected-products list above.

How do I mitigate CVE-2009-1535 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Is CVE-2009-1535 actively exploited in the wild?

Yes. There are 4 known exploit references for CVE-2009-1535, including 2 documented proof-of-concept exploits on Exploit-DB and 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2009-1535?

CVE-2009-1535 has an EPSS (Exploit Prediction Scoring System) score of 98.1%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

What type of vulnerability is CVE-2009-1535?

CVE-2009-1535 is classified as Improper Authentication (CWE-287). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2009-1535?

CVE-2009-1535 affects microsoft internet information services (2 versions, e.g. 5.1, 6.0). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2009-1535 published, and has it been updated?

CVE-2009-1535 was published on June 10, 2009 and was last updated on June 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

Not in CISA KEV

CVE-2009-1535 — Internet Information Services

CVE-2009-1535 is a Improper Authentication vulnerability in microsoft internet information services. 4 public exploit references exist, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.

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,…

Published

Jun 10, 2009

Updated

Jun 16, 2026

Affected

1 product

Patched

See advisory

Exploits

4 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

98.1%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

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

1 product · 2 configurations

Application

internet information servicesmicrosoft

2 versions

5.16.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-8704remotewindows✓ Verified

Microsoft IIS 6.0 - WebDAV Remote Authentication Bypass (1)

by kingcope · May 15, 2009

Exploit-DB Source

EDB-8806remotewindows✓ Verified

Microsoft IIS 6.0 - WebDAV Remote Authentication Bypass (2)

by ka0x · May 26, 2009

Exploit-DB Source

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every microsoft internet information services deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2009-1535 yet — track the microsoft internet information services advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2009-1535 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

Protect my workloads How runtime protection works