{"id":"CVE-2023-28434","aliases":["GHSA-2pxw-r47w-4p8c"],"url":"https://o3.security/vulnerability/CVE-2023-28434","summary":"MinIO is vulnerable to privilege escalation on Linux/MacOS","details":"### Impact\nAn attacker can use crafted requests to bypass metadata bucket name checking and put an object into any bucket while processing `PostPolicyBucket`. To carry out this attack, the attacker requires credentials with `arn:aws:s3:::*` permission, as well as enabled Console API access.\n\n### Patches\n```\ncommit 67f4ba154a27a1b06e48bfabda38355a010dfca5\nAuthor: Aditya Manthramurthy <donatello@users.noreply.github.com>\nDate:   Sun Mar 19 21:15:20 2023 -0700\n\n    fix: post policy request security bypass (#16849)\n```\n\n### Workarounds\nBrowser API access must be enabled turning off `MINIO_BROWSER=off` allows for this workaround.\n\n### References\nThe vulnerable code:\n```go\n// minio/cmd/generic-handlers.go\nfunc setRequestValidityHandler(h http.Handler) http.Handler {\n  return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {\n    // ...\n    // For all other requests reject access to reserved buckets\n    bucketName, _ := request2BucketObjectName(r)\n    if isMinioReservedBucket(bucketName) || isMinioMetaBucket(bucketName) {\n      if !guessIsRPCReq(r) && !guessIsBrowserReq(r) && !guessIsHealthCheckReq(r) && !guessIsMetricsReq(r) && !isAdminReq(r) && !isKMSReq(r) {\n        if ok {\n          tc.FuncName = \"handler.ValidRequest\"\n          tc.ResponseRecorder.LogErrBody = true\n        }\n        writeErrorResponse(r.Context(), w, errorCodes.ToAPIErr(ErrAllAccessDisabled), r.URL)\n        return\n      }\n    }\n    // ...\n```","published":"2023-03-22T20:44:04.216Z","modified":"2026-10-21T23:11:56.658896303Z","cvss":{"score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.06681,"percentile":0.93382,"asOf":"2026-08-25"},"cisaKev":{"dateAdded":"2023-09-19","dueDate":"2023-10-10","knownRansomwareCampaignUse":false},"exploitsKnown":4,"affectedPackages":[{"ecosystem":"Go","name":"github.com/minio/minio","fixedVersion":"0.0.0-202303200415"}],"fix":{"url":"https://github.com/minio/minio/commit/67f4ba154a27a1b06e48bfabda38355a010dfca5","label":"minio/minio@67f4ba1"},"references":[{"type":"WEB","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-28434"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/28xxx/CVE-2023-28434.json"},{"type":"ADVISORY","url":"https://github.com/minio/minio/security/advisories/GHSA-2pxw-r47w-4p8c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-28434"},{"type":"FIX","url":"https://github.com/minio/minio/commit/67f4ba154a27a1b06e48bfabda38355a010dfca5"},{"type":"FIX","url":"https://github.com/minio/minio/pull/16849"},{"type":"PACKAGE","url":"https://github.com/minio/minio"}],"provenance":{"sources":["OSV.dev","CISA KEV","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T23:11:56.658896303Z"}}