# CVE-2021-21287: Server-Side Request Forgery in MinIO Browser API

> Attackers can exploit SSRF in MinIO Browser API to access internal resources and metadata, requiring an upgrade to secure the server.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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:** Yes
- **Published:** 1 Feb 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-m4qq-5f7c-693q, MINI-8rr8-c7x2-hx27, MINI-jvf8-gx44-3h84

## What is CVE-2021-21287?

CVE-2021-21287 is a high-severity server-side request forgery vulnerability in minio, published on 1 Feb 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

MinIO is a High Performance Object Storage released under Apache License v2.0. In MinIO before version RELEASE.2021-01-30T00-20-58Z there is a server-side request forgery vulnerability. The target application may have functionality for importing data from a URL, publishing data to a URL, or otherwise reading data from a URL that can be tampered with. The attacker modifies the calls to this functionality by supplying a completely different URL or by manipulating how URLs are built (path traversal etc.). In a Server-Side Request Forgery (SSRF) attack, the attacker can abuse functionality on the server to read or update internal resources. The attacker can supply or modify a URL which the code running on the server will read or submit data, and by carefully selecting the URLs, the attacker may be able to read server configuration such as AWS metadata, connect to internal services like HTTP enabled databases, or perform post requests towards internal services which are not intended to be exposed. This is fixed in version RELEASE.2021-01-30T00-20-58Z, all users are advised to upgrade. As a workaround you can disable the browser front-end with "MINIO_BROWSER=off" environment variable.

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

## Which versions are affected by CVE-2021-21287?

It affects 1 product.


Products: Minio Minio.

## How do I fix CVE-2021-21287?

Upgrade to a fixed version.

## Is CVE-2021-21287 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21287 exists.

Public exploit code:

- MinIO Browser API - Server-Side Request Forgery (nuclei): http/cves/2021/CVE-2021-21287.yaml

## Other vulnerabilities in minio

- [CVE-2023-28434](https://insights.sbomify.com/CVE-2023-28434/): MinIO Security Feature Bypass (high 8.8, exploited in the wild)
- [CVE-2023-28432](https://insights.sbomify.com/CVE-2023-28432/): MinIO Information Disclosure (high 7.5, exploited in the wild)
- [CVE-2020-11012](https://insights.sbomify.com/CVE-2020-11012/): Authentication bypass MinIO Admin API (critical 9.3)
- [CVE-2026-33322](https://insights.sbomify.com/CVE-2026-33322/): MinIO: JWT Algorithm Confusion in OIDC Authentication (critical 9.2)
- [CVE-2026-33419](https://insights.sbomify.com/CVE-2026-33419/): MinIO: LDAP login brute-force via user enumeration and missing rate limit (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21287 and fix it if it is affected.

What it is: CVE-2021-21287 is a high-severity server-side request forgery vulnerability in minio, published on 1 Feb 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21287 exists.

Affected product: minio. 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-2021-21287/ (Markdown: https://insights.sbomify.com/CVE-2021-21287/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21287
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21287
- OSV: https://osv.dev/vulnerability/CVE-2021-21287

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21287/
Summaries are generated and may contain mistakes; the official description above is the record.