CVE-2021-3906 Unrestricted Upload of File with Dangerous Type in bookstackapp/bookstack
Medium 5.4
Published
Updated
Check this codebase for CVE-2021-3906 and fix it if it is affected.
What it is: CVE-2021-3906 is a medium-severity vulnerability in bookstackapp/bookstack, published on 27 Oct 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-3906 in the wild and no public exploit code.
Affected product: bookstackapp/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-2021-3906/ (Markdown: https://insights.sbomify.com/CVE-2021-3906/index.md)
Attackers can upload dangerous file types to BookStack, potentially leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-3906?
CVE-2021-3906 is a medium-severity vulnerability in bookstackapp/bookstack, published on 27 Oct 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
bookstack is vulnerable to Unrestricted Upload of File with Dangerous Type
Weakness: CWE-434
Which versions are affected by CVE-2021-3906?
It affects 1 product.
Products include Bookstackapp Bookstack.
How do I fix CVE-2021-3906?
No fix has been published for CVE-2021-3906 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-3906 being exploited?
There is no known exploitation of CVE-2021-3906 in the wild and no public exploit code.
Other vulnerabilities in bookstackapp/bookstack
- CVE-2020-5256 Remote Code Execution Through Image Uploads in BookStack
- CVE-2020-26210 Cross-Site Scripting in BookStack
- CVE-2020-26211 Cross-Site Scripting in BookStack
- CVE-2022-0877 Cross-site Scripting (XSS) - Stored in bookstackapp/bookstack
- CVE-2021-3915 Unrestricted Upload of File with Dangerous Type in bookstackapp/bookstack
Sources
Also known as GHSA-qrmv-xr2h-3hrw.