{"id":"CVE-2021-21369","aliases":["EUVD-2021-8681","GHSA-qgfj-mjpc-7w3q"],"status":"published","title":"Potential DoS in Besu HTTP JSON-RPC API","description":"Hyperledger Besu is an open-source, MainNet compatible, Ethereum client written in Java. In Besu before version 1.5.1 there is a denial-of-service vulnerability involving the HTTP JSON-RPC API service. If username and password authentication is enabled for the HTTP JSON-RPC API service, then prior to making any requests to an API endpoint the requestor must use the login endpoint to obtain a JSON web token (JWT) using their credentials. A single user can readily overload the login endpoint with invalid requests (incorrect password). As the supplied password is checked for validity on the main vertx event loop and takes a relatively long time this can cause the processing of other valid requests to fail. A valid username is required for this vulnerability to be exposed. This has been fixed in version 1.5.1.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01668,"percentile":0.77068,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-400"],"published":"2021-03-09T18:10:18Z","modified":"2026-10-20T14:05:10Z","products":[{"vendor":"hyperledger","product":"besu"},{"vendor":"linuxfoundation","product":"besu"}],"references":[{"url":"https://github.com/hyperledger/besu/security/advisories/GHSA-qgfj-mjpc-7w3q","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory"]},{"url":"https://github.com/hyperledger/besu/blob/master/CHANGELOG.md#151","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory"]},{"url":"https://github.com/hyperledger/besu/pull/1144","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://github.com/hyperledger/besu/commit/06e35a58c07a30c0fbdc0aae45a3e8b06b53c022","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix"]}],"sources":{"cve":[{"id":"CVE-2021-21369","title":"Potential DoS in Besu HTTP JSON-RPC API","description":"Hyperledger Besu is an open-source, MainNet compatible, Ethereum client written in Java. In Besu before version 1.5.1 there is a denial-of-service vulnerability involving the HTTP JSON-RPC API service. If username and password authentication is enabled for the HTTP JSON-RPC API service, then prior to making any requests to an API endpoint the requestor must use the login endpoint to obtain a JSON web token (JWT) using their credentials. A single user can readily overload the login endpoint with invalid requests (incorrect password). As the supplied password is checked for validity on the main vertx event loop and takes a relatively long time this can cause the processing of other valid requests to fail. A valid username is required for this vulnerability to be exposed. This has been fixed in version 1.5.1.","status":"published","published":"2021-03-09T18:10:18Z","modified":"2024-08-03T18:09:15.981Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:33:00.488332Z"}],"euvd":[{"id":"EUVD-2021-8681","description":"Hyperledger Besu is an open-source, MainNet compatible, Ethereum client written in Java. In Besu before version 1.5.1 there is a denial-of-service vulnerability involving the HTTP JSON-RPC API service. If username and password authentication is enabled for the HTTP JSON-RPC API service, then prior to making any requests to an API endpoint the requestor must use the login endpoint to obtain a JSON web token (JWT) using their credentials. A single user can readily overload the login endpoint with invalid requests (incorrect password). As the supplied password is checked for validity on the main vertx event loop and takes a relatively long time this can cause the processing of other valid requests to fail. A valid username is required for this vulnerability to be exposed. This has been fixed in version 1.5.1.","status":"published","published":"2021-03-09T18:10:18Z","modified":"2024-08-03T18:09:15Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T03:25:06.347262Z"}],"nvd":[{"id":"CVE-2021-21369","description":"Hyperledger Besu is an open-source, MainNet compatible, Ethereum client written in Java. In Besu before version 1.5.1 there is a denial-of-service vulnerability involving the HTTP JSON-RPC API service. If username and password authentication is enabled for the HTTP JSON-RPC API service, then prior to making any requests to an API endpoint the requestor must use the login endpoint to obtain a JSON web token (JWT) using their credentials. A single user can readily overload the login endpoint with invalid requests (incorrect password). As the supplied password is checked for validity on the main vertx event loop and takes a relatively long time this can cause the processing of other valid requests to fail. A valid username is required for this vulnerability to be exposed. This has been fixed in version 1.5.1.","status":"published","published":"2021-03-09T18:15:18.047Z","modified":"2026-06-17T03:35:24.457Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4,"vector":"AV:N/AC:L/Au:S/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:06:50.399901Z"}],"osv":[{"id":"CVE-2021-21369","description":"Hyperledger Besu is an open-source, MainNet compatible, Ethereum client written in Java. In Besu before version 1.5.1 there is a denial-of-service vulnerability involving the HTTP JSON-RPC API service. If username and password authentication is enabled for the HTTP JSON-RPC API service, then prior to making any requests to an API endpoint the requestor must use the login endpoint to obtain a JSON web token (JWT) using their credentials. A single user can readily overload the login endpoint with invalid requests (incorrect password). As the supplied password is checked for validity on the main vertx event loop and takes a relatively long time this can cause the processing of other valid requests to fail. A valid username is required for this vulnerability to be exposed. This has been fixed in version 1.5.1.","status":"published","published":"2021-03-09T18:15:18.047Z","modified":"2026-10-20T14:05:10.281122039Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:18.004149Z"}]}}