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

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

Which versions are affected by CVE-2021-21287?

It affects 1 product.

Products include Minio Minio.

How do I fix CVE-2021-21287?

Upgrade to a fixed version.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

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: 1 Nuclei template.

Other vulnerabilities in minio

• CVE-2023-28434 MinIO Security Feature Bypass Exploited High 8.8
• CVE-2023-28432 MinIO Information Disclosure Exploited High 7.5
• CVE-2020-11012 Authentication bypass MinIO Admin API Critical 9.3
• CVE-2026-33322 MinIO: JWT Algorithm Confusion in OIDC Authentication Critical 9.2
• CVE-2026-33419 MinIO: LDAP login brute-force via user enumeration and missing rate limit Critical 9.1

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-m4qq-5f7c-693q, MINI-8rr8-c7x2-hx27, MINI-jvf8-gx44-3h84.