Windows Server 2003 & IIS 6.0 - Remote Code Execution

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

criticalseverity

9.8CVSS score

99.8%likelihood of exploitation, next 30 days

100%of all CVEs are less likely

Readycheck to confirm it

Internet Information Services (IIS) 6.0 in Microsoft Windows Server 2003 R2 contains a buffer overflow vulnerability in the ScStoragePathFromUrl function in the WebDAV service that could allow remote attackers to execute arbitrary code via a long header beginning with "If <http://" in a PROPFIND request.

Impact

Allows remote attackers to execute arbitrary code on the affected system.

Fix

Upgrade to a supported version of Windows Server and IIS, or apply the necessary security patches.

How to confirm it

Send: OPTIONS {{BaseURL}}
Positive when: regex("<DAV:sql>", dasl) or regex("[\d]+(,\s+[\d]+)?", dav) or regex(".*?PROPFIND", public) or regex(".*?PROPFIND", allow) AND contains in header "IIS/6.0" AND status 200

Run it with nuclei: nuclei -id CVE-2017-7269 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2017-7269

info:
  name: Windows Server 2003 & IIS 6.0 - Remote Code Execution
  author: thomas_from_offensity,geeknik
  severity: critical
  description: |
    Internet Information Services (IIS) 6.0 in Microsoft Windows Server 2003 R2 contains a buffer overflow vulnerability in the ScStoragePathFromUrl function in the WebDAV service that could allow remote attackers to execute arbitrary code via a long header beginning with "If <http://" in a PROPFIND request.
  impact: |
    Allows remote attackers to execute arbitrary code on the affected system.
  remediation: |
    Upgrade to a supported version of Windows Server and IIS, or apply the necessary security patches.
  reference:
    - https://blog.0patch.com/2017/03/0patching-immortal-cve-2017-7269.html
    - https://github.com/danigargu/explodingcan/blob/master/explodingcan.py
    - https://nvd.nist.gov/vuln/detail/CVE-2017-7269
    - https://github.com/edwardz246003/IIS_exploit
    - http://www.securitytracker.com/id/1038168
  classification:
    cvss-metrics: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2017-7269
    cwe-id: CWE-119
    epss-score: 0.99823
    epss-percentile: 0.9996
    cpe: cpe:2.3:a:microsoft:internet_information_server:6.0:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: microsoft
    product: internet_information_server
    shodan-query: cpe:"cpe:2.3:a:microsoft:internet_information_server"
  tags: cve2017,cve,rce,windows,iis,kev,microsoft,vkev,vuln

http:
  - method: OPTIONS
    path:
      - "{{BaseURL}}"

    matchers-condition: and
    matchers:
      - type: dsl
        dsl:
          - regex("<DAV:sql>", dasl)
          - regex("[\d]+(,\s+[\d]+)?", dav)
          - regex(".*?PROPFIND", public)
          - regex(".*?PROPFIND", allow)
        condition: or

      - type: word
        part: header
        words:
          - "IIS/6.0"

      - type: status
        status:
          - 200

References

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