# CVE-2023-6199: Book Stack v23.10.2 - LFR via Blind SSRF

> An attacker can exploit Server-Side Request Forgery in BookStack to filter and read local files on the server.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Nov 2023
- **Updated:** 19 May 2025
- **Also known as:** GHSA-fwg4-q55q-w62p

## What is CVE-2023-6199?

CVE-2023-6199 is a medium-severity server-side request forgery vulnerability in BookStack, published on 20 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Book Stack version 23.10.2 allows filtering local files on the server. This is possible because the application is vulnerable to SSRF.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2023-6199?

It affects 1 product.


Products: Bookstackapp Bookstack.

## How do I fix CVE-2023-6199?

No fix has been published for CVE-2023-6199 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-6199 being exploited?

There is no known exploitation of CVE-2023-6199 in the wild and no public exploit code.

Public exploit code:

- PoC scripts to exploit LFR (Local File Read) via PHP filters chain oracle (php://filter), especially for CTF purposes or the exploit of CVE-2023-6199, etc. This's a one-script exploitation PoC modified from https://github.com/synacktiv/php_filter_chains_oracle_exploit (github_poc): https://github.com/4xura/php_filter_chain_oracle_poc
- A CLI to exploit parameters vulnerable to PHP filter chain error based oracle, modified to exploit CVE-2023-6199 (github_poc): https://github.com/AbdrrahimDahmani/php_filter_chains_oracle_exploit_for_CVE-2023-6199

## Other vulnerabilities in BookStack

- [CVE-2020-5256](https://insights.sbomify.com/CVE-2020-5256/): Remote Code Execution Through Image Uploads in BookStack (high 7.9)
- [CVE-2020-26210](https://insights.sbomify.com/CVE-2020-26210/): Cross-Site Scripting in BookStack (high 7.7)
- [CVE-2020-26211](https://insights.sbomify.com/CVE-2020-26211/): Cross-Site Scripting in BookStack (high 7.7)
- [CVE-2022-0877](https://insights.sbomify.com/CVE-2022-0877/): Cross-site Scripting (XSS) - Stored in bookstackapp/bookstack (high 7.6)
- [CVE-2021-3915](https://insights.sbomify.com/CVE-2021-3915/): Unrestricted Upload of File with Dangerous Type in bookstackapp/bookstack (high 7.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-6199 and fix it if it is affected.

What it is: CVE-2023-6199 is a medium-severity server-side request forgery vulnerability in BookStack, published on 20 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-6199 in the wild and no public exploit code.

Affected product: BookStack. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-6199/ (Markdown: https://insights.sbomify.com/CVE-2023-6199/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-6199
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-6199
- OSV: https://osv.dev/vulnerability/CVE-2023-6199

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-6199/
Summaries are generated and may contain mistakes; the official description above is the record.