{"id":"BIT-minio-2021-21390","summary":"MITM modification of request bodies in MinIO","details":"MinIO is an open-source high performance object storage service and it is API compatible with Amazon S3 cloud storage service. In MinIO before version RELEASE.2021-03-17T02-33-02Z, there is a vulnerability which enables MITM modification of request bodies that are meant to have integrity guaranteed by chunk signatures. In a PUT request using aws-chunked encoding, MinIO ordinarily verifies signatures at the end of a chunk. This check can be skipped if the client sends a false chunk size that is much greater than the actual data sent: the server accepts and completes the request without ever reaching the end of the chunk + thereby without ever checking the chunk signature. This is fixed in version RELEASE.2021-03-17T02-33-02Z. As a workaround one can avoid using \"aws-chunked\" encoding-based chunk signature upload requests instead use TLS. MinIO SDKs automatically disable chunked encoding signature when the server endpoint is configured with TLS.","aliases":["CVE-2021-21390","GHSA-xr7r-7gpj-5pgp"],"modified":"2026-09-08T08:47:42.320105122Z","published":"2024-03-06T10:58:02.168Z","database_specific":{"severity":"Medium","cpes":["cpe:2.3:a:minio:minio:*:*:*:*:*:*:*:*"]},"references":[{"type":"ADVISORY","url":"https://github.com/minio/minio/commit/e197800f9055489415b53cf137e31e194aaf7ba0"},{"type":"ADVISORY","url":"https://github.com/minio/minio/pull/11801"},{"type":"ADVISORY","url":"https://github.com/minio/minio/security/advisories/GHSA-xr7r-7gpj-5pgp"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21390"}],"affected":[{"package":{"name":"minio","ecosystem":"Bitnami","purl":"pkg:bitnami/minio"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2021.03.17"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/minio/BIT-minio-2021-21390.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}],"schema_version":"1.9.0"}