{"api_version":"1","generated_at":"2026-04-22T23:09:31+00:00","cve":"CVE-2021-21390","urls":{"html":"https://cve.report/CVE-2021-21390","api":"https://cve.report/api/cve/CVE-2021-21390.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-21390","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-21390"},"summary":{"title":"CVE-2021-21390","description":"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.","state":"PUBLIC","assigner":"security-advisories@github.com","published_at":"2021-03-19 16:15:00","updated_at":"2021-03-25 20:29:00"},"problem_types":["CWE-924"],"metrics":[],"references":[{"url":"https://github.com/minio/minio/security/advisories/GHSA-xr7r-7gpj-5pgp","name":"https://github.com/minio/minio/security/advisories/GHSA-xr7r-7gpj-5pgp","refsource":"CONFIRM","tags":[],"title":"Chunked body signature check not always applied · Advisory · minio/minio · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"0"},{"url":"https://github.com/minio/minio/pull/11801","name":"https://github.com/minio/minio/pull/11801","refsource":"MISC","tags":[],"title":"s3v4: read and verify S3 signature v4 chunks separately by aead · Pull Request #11801 · minio/minio · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://github.com/minio/minio/commit/e197800f9055489415b53cf137e31e194aaf7ba0","name":"https://github.com/minio/minio/commit/e197800f9055489415b53cf137e31e194aaf7ba0","refsource":"MISC","tags":[],"title":"s3v4: read and verify S3 signature v4 chunks separately (#11801) · minio/minio@e197800 · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-21390","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21390","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"21390","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"minio","cpe5":"minio","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2021-21390","STATE":"PUBLIC","TITLE":"MITM modification of request bodies in MinIO"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"minio","version":{"version_data":[{"version_value":"< RELEASE.2021-03-17T02-33-02Z"}]}}]},"vendor_name":"minio"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"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."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-924: Improper Enforcement of Message Integrity During Transmission in a Communication Channel"}]}]},"references":{"reference_data":[{"name":"https://github.com/minio/minio/security/advisories/GHSA-xr7r-7gpj-5pgp","refsource":"CONFIRM","url":"https://github.com/minio/minio/security/advisories/GHSA-xr7r-7gpj-5pgp"},{"name":"https://github.com/minio/minio/pull/11801","refsource":"MISC","url":"https://github.com/minio/minio/pull/11801"},{"name":"https://github.com/minio/minio/commit/e197800f9055489415b53cf137e31e194aaf7ba0","refsource":"MISC","url":"https://github.com/minio/minio/commit/e197800f9055489415b53cf137e31e194aaf7ba0"}]},"source":{"advisory":"GHSA-xr7r-7gpj-5pgp","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2021-03-19 16:15:00","lastModifiedDate":"2021-03-25 20:29:00","problem_types":["CWE-924"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":5.9,"baseSeverity":"MEDIUM"},"exploitabilityScore":2.2,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:M/Au:N/C:N/I:P/A:N","accessVector":"NETWORK","accessComplexity":"MEDIUM","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"PARTIAL","availabilityImpact":"NONE","baseScore":4.3},"severity":"MEDIUM","exploitabilityScore":8.6,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:minio:minio:*:*:*:*:*:*:*:*","versionEndExcluding":"2021-03-17t02-33-02z","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"21390","Ordinal":"195516","Title":"CVE-2021-21390","CVE":"CVE-2021-21390","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"21390","Ordinal":"1","NoteData":"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.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"21390","Ordinal":"2","NoteData":"2021-03-19","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"21390","Ordinal":"3","NoteData":"2021-03-19","Type":"Other","Title":"Modified"}]}}}