{"id":"CVE-2021-22160","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-22160","generatedAt":"2026-11-05T01:17:44.342Z","title":"This allows an attacker to connect to Pulsar instances as any user (incl. admins).","description":"If Apache Pulsar is configured to authenticate clients using tokens based on JSON Web Tokens (JWT), the signature of the token is not validated if the algorithm of the presented token is set to \"none\". This allows an attacker to connect to Pulsar instances as any user (incl. admins).","published":"2021-05-26T13:15:08.000Z","lastModified":"2026-06-17T03:36:43.000Z","status":"Modified","sourceIdentifier":"security@apache.org","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-347"],"affected":["apache/pulsar"],"epss":{"score":0.52926,"percentile":0.98977,"date":"2026-11-03","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 52.9%, higher than 99% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"https://lists.apache.org/thread.html/r347650d15a3e9c5f58b83e918b6ad6dedc2a63d3eb63da8e6a7be87e%40%3Cusers.pulsar.apache.org%3E","tags":["Mailing List","Vendor Advisory"],"source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r8e545559781231a83bf0644548c660255859e52feb86bbfcd42590da%40%3Cdev.pulsar.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r9a12b4da2f26ce9b8f7e7117a879efaa973dab7e54717bbc7923fab1%40%3Cdev.pulsar.apache.org%3E","tags":["Mailing List","Vendor Advisory"],"source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/ra49cb62105154e4795b259c79a6b27d63bfa2ab5787ff8529b089550%40%3Cdev.pulsar.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/ra49cb62105154e4795b259c79a6b27d63bfa2ab5787ff8529b089550%40%3Cusers.pulsar.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/rbe845aa1573a61769b9c5916c62971f4b10de87c2ea5f38a97f0cf84%40%3Cdev.pulsar.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/rca54f4b26ba5e6f2e39732b47ec51640e89f57e3b6a38ac3bab314df%40%3Cdev.pulsar.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/rf2e90942996dceebac8296abf39257cfeb5ae918f82f7af3d37a48c5%40%3Cdev.pulsar.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r347650d15a3e9c5f58b83e918b6ad6dedc2a63d3eb63da8e6a7be87e%40%3Cusers.pulsar.apache.org%3E","tags":["Mailing List","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r8e545559781231a83bf0644548c660255859e52feb86bbfcd42590da%40%3Cdev.pulsar.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r9a12b4da2f26ce9b8f7e7117a879efaa973dab7e54717bbc7923fab1%40%3Cdev.pulsar.apache.org%3E","tags":["Mailing List","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/ra49cb62105154e4795b259c79a6b27d63bfa2ab5787ff8529b089550%40%3Cdev.pulsar.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/ra49cb62105154e4795b259c79a6b27d63bfa2ab5787ff8529b089550%40%3Cusers.pulsar.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rbe845aa1573a61769b9c5916c62971f4b10de87c2ea5f38a97f0cf84%40%3Cdev.pulsar.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rca54f4b26ba5e6f2e39732b47ec51640e89f57e3b6a38ac3bab314df%40%3Cdev.pulsar.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rf2e90942996dceebac8296abf39257cfeb5ae918f82f7af3d37a48c5%40%3Cdev.pulsar.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-22160","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}