{"id":"CVE-2021-27905","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-27905","generatedAt":"2026-11-05T01:35:26.909Z","title":"To prevent a SSRF vulnerability, Solr ought to check these parameters against a similar configuration it uses for the \"shards\" parameter.","description":"The ReplicationHandler (normally registered at \"/replication\" under a Solr core) in Apache Solr has a \"masterUrl\" (also \"leaderUrl\" alias) parameter that is used to designate another ReplicationHandler on another Solr core to replicate index data into the local core. To prevent a SSRF vulnerability, Solr ought to check these parameters against a similar configuration it uses for the \"shards\" parameter. Prior to this bug getting fixed, it did not. This problem affects essentially all Solr versions prior to it getting fixed in 8.8.2.","published":"2021-04-13T07:15:12.000Z","lastModified":"2026-06-17T03:45:35.000Z","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-918"],"affected":["apache/solr"],"epss":{"score":0.93053,"percentile":0.99833,"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 93.1%, higher than 100% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"https://lists.apache.org/thread.html/r0ddc3a82bd7523b1453cb7a5e09eb5559517145425074a42eb326b10%40%3Cannounce.apache.org%3E","tags":["Mailing List","Vendor Advisory"],"source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r140128dc6bb4f4e0b6a39e962c7ca25a8cbc8e48ed766176c931fccc%40%3Cusers.solr.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r3da74965aba2b5f5744b7289ad447306eeb2940c872801819faa9314%40%3Cusers.solr.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r6ccec7fc54d82591b23c143f1f6a6e38f6e03e75db70870e4cb14a1a%40%3Ccommits.ofbiz.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r720a4a0497fc90bad5feec8aa18b777912ee15c7eeb5f882adbf523e%40%3Ccommits.ofbiz.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r78a3a4f1138a1608b0c6d4a2ee7647848c1a20b0d5c652cd9b02c25a%40%3Ccommits.ofbiz.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r8f1152a43c36d878bbeb5a92f261e9efaf3af313b033d7acfccea59d%40%3Cnotifications.ofbiz.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r95df34bb158375948da82b4dfe9a1b5d528572d586584162f8f5aeef%40%3Cusers.solr.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/rae9ccaecce9859f709ed1458545d90a4c07163070dc98b5e9e59057f%40%3Cnotifications.ofbiz.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/rd232d77c57a8ce172359ab098df9512d8b37373ab87c444be911b430%40%3Cnotifications.ofbiz.apache.org%3E","source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/re9d64bb8e5dfefddcbf255adb4559e13a0df5b818da1b9b51329723f%40%3Cnotifications.ofbiz.apache.org%3E","source":"security@apache.org"},{"url":"https://security.netapp.com/advisory/ntap-20210611-0009/","tags":["Third Party Advisory"],"source":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/r0ddc3a82bd7523b1453cb7a5e09eb5559517145425074a42eb326b10%40%3Cannounce.apache.org%3E","tags":["Mailing List","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r140128dc6bb4f4e0b6a39e962c7ca25a8cbc8e48ed766176c931fccc%40%3Cusers.solr.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r3da74965aba2b5f5744b7289ad447306eeb2940c872801819faa9314%40%3Cusers.solr.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r6ccec7fc54d82591b23c143f1f6a6e38f6e03e75db70870e4cb14a1a%40%3Ccommits.ofbiz.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r720a4a0497fc90bad5feec8aa18b777912ee15c7eeb5f882adbf523e%40%3Ccommits.ofbiz.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r78a3a4f1138a1608b0c6d4a2ee7647848c1a20b0d5c652cd9b02c25a%40%3Ccommits.ofbiz.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r8f1152a43c36d878bbeb5a92f261e9efaf3af313b033d7acfccea59d%40%3Cnotifications.ofbiz.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r95df34bb158375948da82b4dfe9a1b5d528572d586584162f8f5aeef%40%3Cusers.solr.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rae9ccaecce9859f709ed1458545d90a4c07163070dc98b5e9e59057f%40%3Cnotifications.ofbiz.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rd232d77c57a8ce172359ab098df9512d8b37373ab87c444be911b430%40%3Cnotifications.ofbiz.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/re9d64bb8e5dfefddcbf255adb4559e13a0df5b818da1b9b51329723f%40%3Cnotifications.ofbiz.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20210611-0009/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-27905","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."}