VMware vCenter Server LDAP Broken Access Control

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

criticalseverity

9.8CVSS score

90.4%likelihood of exploitation, next 30 days

100%of all CVEs are less likely

Readycheck to confirm it

Under certain conditions, vmdir that ships with VMware vCenter Server, as part of an embedded or external Platform Services Controller (PSC), does not correctly implement access controls.

Impact

Unauthorized users may access sensitive functions, potentially leading to privilege escalation or data exposure.

Fix

Apply the latest security patches and updates provided by VMware to address access control issues.

How to confirm it

Send: POST /sdk/
Positive when: contains "RetrieveServiceContentResponse" or "urn:vim" AND contains in content_type "text/xml" AND status 200 AND compare_versions(version, '< 6.7.0')

Run it with nuclei: nuclei -id CVE-2020-3952 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2020-3952

info:
  name: VMware vCenter Server LDAP Broken Access Control
  author: 0x_Akoko
  severity: critical
  description: |
    Under certain conditions, vmdir that ships with VMware vCenter Server, as part of an embedded or external Platform Services Controller (PSC), does not correctly implement access controls.
  impact: |
    Unauthorized users may access sensitive functions, potentially leading to privilege escalation or data exposure.
  remediation: |
    Apply the latest security patches and updates provided by VMware to address access control issues.
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2020-3952
    - https://www.vmware.com/security/advisories/VMSA-2020-0006.html
    - https://github.com/guardicore/vmware_vcenter_cve_2020_3952
  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-2020-3952
    cwe-id: CWE-306
    epss-score: 0.90384
    epss-percentile: 0.99802
    cpe: cpe:2.3:a:vmware:vcenter_server:6.7:-:*:*:*:*:*:*
  metadata:
    verified: false
    max-request: 1
    vendor: vmware
    product: vcenter_server
  tags: cve,cve2020,vmware,vcenter,ldap,auth-bypass,passive,kev,vkev,vuln

http:
  - raw:
      - |
        POST /sdk/ HTTP/1.1
        Host: {{Hostname}}
        Content-Type: text/xml
        SOAPAction: "urn:vim25/6.5"

        <?xml version="1.0" encoding="UTF-8"?>
        <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
           <soap:Header>
              <operationID>00000001-00000001</operationID>
           </soap:Header>
           <soap:Body>
              <RetrieveServiceContent xmlns="urn:internalvim25">
                 <_this xsi:type="ManagedObjectReference" type="ServiceInstance">ServiceInstance</_this>
              </RetrieveServiceContent>
           </soap:Body>
        </soap:Envelope>

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - 'RetrieveServiceContentResponse'
          - 'urn:vim'
        condition: or

      - type: word
        part: content_type
        words:
          - "text/xml"

      - type: status
        status:
          - 200

      - type: dsl
        dsl:
          - compare_versions(version, '< 6.7.0')

    extractors:
      - type: regex
        part: body
        name: version
        group: 1
        regex:
          - "<version>([^<]+)</version>"

References

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