Vulnerabilities > CVE-2009-1535 - Improper Authentication vulnerability in Microsoft Internet Information Services 5.1/6.0

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
microsoft
CWE-287
nessus
exploit available
metasploit

Summary

The WebDAV extension in Microsoft Internet Information Services (IIS) 5.1 and 6.0 allows remote attackers to bypass URI-based protection mechanisms, and list folders or read, create, or modify files, via a %c0%af (Unicode / character) at an arbitrary position in the URI, as demonstrated by inserting %c0%af into a "/protected/" initial pathname component to bypass the password protection on the protected\ folder, aka "IIS 5.1 and 6.0 WebDAV Authentication Bypass Vulnerability," a different vulnerability than CVE-2009-1122.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.

Exploit-Db

descriptionMicrosoft IIS 6.0 WebDAV Remote Authentication Bypass Vulnerability. CVE-2009-1535,CVE-2009-1676. Remote exploit for windows platform
idEDB-ID:8704
last seen2016-02-01
modified2009-05-15
published2009-05-15
reporterkingcope
sourcehttps://www.exploit-db.com/download/8704/
titleMicrosoft IIS 6.0 WebDAV - Remote Authentication Bypass Vulnerability

Metasploit

Msbulletin

bulletin_idMS09-020
bulletin_url
date2009-06-09T00:00:00
impactElevation of Privilege
knowledgebase_id970483
knowledgebase_url
severityImportant
titleVulnerabilities in Internet Information Services (IIS) Could Allow Elevation of Privilege

Nessus

  • NASL familyWindows : Microsoft Bulletins
    NASL idSMB_NT_MS09-020.NASL
    descriptionDue to a flaw in the WebDAV extension for IIS, an anonymous, remote attacker may be able to bypass authentication by sending a specially crafted HTTP request and gain access to a protected location.
    last seen2020-06-01
    modified2020-06-02
    plugin id39342
    published2009-06-10
    reporterThis script is Copyright (C) 2009-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/39342
    titleMS09-020: Vulnerabilities in Internet Information Services (IIS) Could Allow Elevation of Privilege (970483)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    
    include("compat.inc");
    
    
    if (description)
    {
      script_id(39342);
      script_version("1.30");
      script_cvs_date("Date: 2018/11/15 20:50:30");
    
      script_cve_id("CVE-2009-1122", "CVE-2009-1535");
      script_bugtraq_id(34993);
      script_xref(name:"MSFT", value:"MS09-020");
      script_xref(name:"MSKB", value:"970483");
      script_xref(name:"EDB-ID", value:"8704");
    
      script_name(english:"MS09-020: Vulnerabilities in Internet Information Services (IIS) Could Allow Elevation of Privilege (970483)");
      script_summary(english:"Checks version of Httpext.dll");
    
      script_set_attribute(attribute:"synopsis", value:"It is possible to bypass authentication on the remote web server.");
      script_set_attribute(attribute:"description", value:
    "Due to a flaw in the WebDAV extension for IIS, an anonymous, remote
    attacker may be able to bypass authentication by sending a specially
    crafted HTTP request and gain access to a protected location.");
      script_set_attribute(attribute:"see_also", value:"https://docs.microsoft.com/en-us/security-updates/SecurityBulletins/2009/ms09-020");
      script_set_attribute(attribute:"solution", value:"Microsoft has released a set of patches for Windows 2000, XP and 2003.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    script_cwe_id(287);
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2009/05/15");
      script_set_attribute(attribute:"patch_publication_date", value:"2009/06/09");
      script_set_attribute(attribute:"plugin_publication_date", value:"2009/06/10");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:microsoft:windows");
      script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:iis");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"Windows : Microsoft Bulletins");
    
      script_copyright(english:"This script is Copyright (C) 2009-2018 Tenable Network Security, Inc.");
    
      script_dependencies("smb_hotfixes.nasl", "ms_bulletin_checks_possible.nasl");
      script_require_keys("SMB/MS_Bulletin_Checks/Possible");
      script_require_ports(139, 445, 'Host/patch_management_checks');
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("smb_func.inc");
    include("smb_hotfixes.inc");
    include("smb_hotfixes_fcheck.inc");
    include("misc_func.inc");
    
    get_kb_item_or_exit("SMB/MS_Bulletin_Checks/Possible");
    
    bulletin = 'MS09-020';
    kb = "970483";
    
    kbs = make_list(kb);
    if (get_kb_item("Host/patch_management_checks")) hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_HOLE);
    
    
    get_kb_item_or_exit("SMB/Registry/Enumerated");
    get_kb_item_or_exit("SMB/WindowsVersion", exit_code:1);
    
    if (hotfix_check_sp_range(win2k:'4,5', xp:'2,3', win2003:'2') <= 0) audit(AUDIT_OS_SP_NOT_VULN);
    if (hotfix_check_iis_installed() <= 0) audit(AUDIT_NOT_INST, "IIS");
    
    rootfile = hotfix_get_systemroot();
    if (!rootfile) exit(1, "Failed to get the system root.");
    
    share = hotfix_path2share(path:rootfile);
    if (!is_accessible_share(share:share)) audit(AUDIT_SHARE_FAIL, share);
    
    if (
      # Windows 2003
      hotfix_is_vulnerable(os:"5.2", sp:2, file:"Httpext.dll", version:"6.0.3790.4518", dir:"\system32\inetsrv", bulletin:bulletin, kb:kb) ||
    
      # Windows XP
      hotfix_is_vulnerable(os:"5.1", sp:3, file:"Httpext.dll", version:"6.0.2600.5817", dir:"\system32\inetsrv", bulletin:bulletin, kb:kb) ||
      hotfix_is_vulnerable(os:"5.1", sp:2, file:"Httpext.dll", version:"6.0.2600.3574", dir:"\system32\inetsrv", bulletin:bulletin, kb:kb) ||
    
      # Windows 2000
      hotfix_is_vulnerable(os:"5.0", file:"Httpext.dll", version:"5.0.2195.7290", dir:"\system32\inetsrv", bulletin:bulletin, kb:kb)
    )
    {
      set_kb_item(name:"SMB/Missing/"+bulletin, value:TRUE);
      hotfix_security_hole();
      hotfix_check_fversion_end();
      exit(0);
    }
    else
    {
      hotfix_check_fversion_end();
      audit(AUDIT_HOST_NOT, 'affected');
    }
    
  • NASL familyWeb Servers
    NASL idWEBDAV_IIS6_FLAW.NASL
    descriptionIIS 6.0 does not properly sanitize WebDAV requests. It is possible to access protected resources by inserting a Unicode / (%c0%af) in the URL. Depending on the remote server configuration, protected resources may be browsed, read and/or modified.
    last seen2020-06-01
    modified2020-06-02
    plugin id38808
    published2009-05-18
    reporterThis script is Copyright (C) 2009-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/38808
    titleMicrosoft IIS WebDAV Unicode Request Directory Security Bypass
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if(description)
    {
     script_id(38808);
     script_version ("1.21");
    
     script_cve_id("CVE-2009-1535");
     script_bugtraq_id(34993);
     script_xref(name: "AUSCERT", value: "AL-2009.0041");
     script_xref(name: "CERTA", value: "CERTA-2009-ALE-007");
     script_xref(name: "CERT-FI", value: "038/2009");
     script_xref(name: "EDB-ID", value: "8704");
    
     script_name(english:"Microsoft IIS WebDAV Unicode Request Directory Security Bypass");
     script_summary(english: "Circumvent IIS 6.0 access control with WebDAV");
    
     script_set_attribute(attribute:"synopsis", value:
    "It is possible to access protected resources through WebDAV." );
     script_set_attribute(attribute:"description", value:
    "IIS 6.0 does not properly sanitize WebDAV requests.  It is possible
    to access protected resources by inserting a Unicode / (%c0%af) in the
    URL. 
    
    Depending on the remote server configuration, protected resources may
    be browsed, read and/or modified." );
     script_set_attribute(attribute:"see_also", value: "http://blog.zoller.lu/2009/05/iis-6-webdac-auth-bypass-and-data.html");
     script_set_attribute(attribute:"see_also", value: "http://www.nessus.org/u?36818b28");
     script_set_attribute(attribute:"see_also", value: "http://www.nessus.org/u?5fefdfc0");
     script_set_attribute(attribute:"see_also", value: "https://isc.sans.edu/diary/IIS6.0+WebDav+Remote+Auth+Bypass/6397");
     script_set_attribute(attribute:"see_also", value: "https://docs.microsoft.com/en-us/security-updates/SecurityAdvisories/2009/971492");
     script_set_attribute(attribute:"see_also", value: "http://unixwiz.net/techtips/ms971492-webdav-vuln.html");
     script_set_attribute(attribute:"see_also", value: "https://forums.iis.net/t/1149348.aspx");
     script_set_attribute(attribute:"solution", value:
    "Disable WebDAV or update the server.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    script_cwe_id(287);
     script_set_attribute(attribute:"plugin_publication_date", value: "2009/05/18");
     script_cvs_date("Date: 2018/11/15 20:50:26");
     script_set_attribute(attribute:"plugin_type", value:"remote");
     script_end_attributes();
    
     script_category(ACT_ATTACK); 
     script_copyright(english:"This script is Copyright (C) 2009-2018 Tenable Network Security, Inc.");
     script_family(english: "Web Servers");
    
     script_dependencie("http_version.nasl", 
      "webmirror.nasl", 
      "http_version.nasl", 
      "DDI_Directory_Scanner.nasl", 
      "no404.nasl", 
      "webdav_enabled.nasl"
     );
     script_exclude_keys("Settings/disable_cgi_scanning");
     script_require_ports("Services/www", 80);
     exit(0);
    }
    
    #
    
    include("global_settings.inc");
    include("misc_func.inc");
    include("http.inc");
    
    port = get_http_port(default:80);
    
    if (report_paranoia < 1)
    {
      banner = get_http_banner(port: port);
      if ("Microsoft-IIS/" >!< banner) exit(0);
    }
    
    # We could check www/PORT/webdav but WebDAV may be enabled only for some directories
    
    prot_url_l = get_kb_list("www/"+port+"/content/basic_auth/url/*");
    
    if (! isnull(prot_url_l))
    {
      prot_url_l = make_list(prot_url_l);
      for (i = 0; ! isnull(prot_url_l[i]); i ++)
      {
        # Make sure that the page requires authentication
        r = http_send_recv3(method: "GET", item: prot_url_l[i], port: port);
        if (isnull(r)) exit(0);
        if (r[0] !~ "^HTTP/1\.[01] 401 ") continue;
    
        h = make_array("Translate", "f");
        u = "/..%c0%af" + prot_url_l[i];
    
        r = http_send_recv3(method: "GET", port: port, item: u);
        if (isnull(r)) exit(0);
        if (r[0] =~ "^HTTP/1\.[01] 200 ") break;
    
        r = http_send_recv3(method: "GET", port: port, item: u, add_headers: h);
        if (isnull(r)) exit(0);
        if (r[0] =~ "^HTTP/1\.[01] 200 ")
        {
          security_hole(port);
          exit(0);
        }
        break;
      }
    }
    
    prot_dir_l = get_kb_list("www/"+port+"/content/directories/auth_required");
    if (! isnull(prot_dir_l))
    {
      xml = 
    '<?xml version="1.0" encoding="utf-8"?>\r\n'+
    '<propfind xmlns="DAV:"><prop>\r\n' +
    '<getcontentlength xmlns="DAV:"/>\r\n'+
    '<getlastmodified xmlns="DAV:"/>\r\n' +
    '<executable xmlns="http://apache.org/dav/props/"/>\r\n' +
    '<resourcetype xmlns="DAV:"/>\r\n' +
    '<checked-in xmlns="DAV:"/>\r\n' +
    '<checked-out xmlns="DAV:"/>\r\n' +
    '</prop></propfind>\r\n';
    
      h = make_array( "Depth", "1", 
          		  "Connection", "TE", 
    		  "TE", "trailers",
    		  "Content-Type", "application/xml" );
    
      prot_dir_l = make_list(prot_dir_l);
      dir = NULL;
      for (i = 0; ! isnull(prot_dir_l[i]); i ++)
        if (strlen(prot_dir_l[i]) > 2)
        {
          # Make sure the page requires authentication
          r = http_send_recv3(method: "PROPFIND", item: prot_dir_l[i], port: port,
          	add_headers: h, data: xml);
          if (isnull(r)) exit(0);
          if (r[0] !~ "^HTTP/1\.[01] 401 ") continue;
    
          dir = strcat(substr(prot_dir_l[i], 0, 1), "%c0%af", substr(prot_dir_l[i], 2));
          break;
        }
      if (isnull(dir)) exit(0);
    
      r = http_send_recv3(port: port, method: "PROPFIND", item: dir,
        add_headers: h, data: xml );
      if (isnull(r)) exit(0);
    
      if ( r[0] =~ "^HTTP/1\.[01] 200 " ||
          (r[0] =~ "^HTTP/1\.[01] 207 " && "<a:status>HTTP/1.1 200 OK</a:status>" >< r[2]))
      {
        if (report_verbosity < 1)
          security_hole(port);
        else
        {
          if (report_verbosity == 1)
            extra = strcat('The following HTTP request got a 20x code instead of 401 :\n\n', http_last_sent_request());
          else
            extra = strcat('The following HTTP request :\n----------\n\n', http_last_sent_request(), '\n--------\nproduced this output :\n\n', r[0], r[1], '\n', r[2], '\n');
          security_hole(port:port, extra: extra);
        }
      }
    }
    

Oval

accepted2009-07-21T07:45:59.612-04:00
classvulnerability
contributors
  • nameDragos Prisaca
    organizationGideon Technologies, Inc.
  • nameDragos Prisaca
    organizationGideon Technologies, Inc.
  • nameDragos Prisaca
    organizationGideon Technologies, Inc.
  • nameDragos Prisaca
    organizationGideon Technologies, Inc.
  • nameDragos Prisaca
    organizationGideon Technologies, Inc.
  • nameDragos Prisaca
    organizationGideon Technologies, Inc.
definition_extensions
  • commentMicrosoft Windows XP (x86) SP2 is installed
    ovaloval:org.mitre.oval:def:754
  • commentMicrosoft IIS 5.1 is installed
    ovaloval:org.mitre.oval:def:460
  • commentMicrosoft Windows XP (x86) SP3 is installed
    ovaloval:org.mitre.oval:def:5631
  • commentMicrosoft IIS 5.1 is installed
    ovaloval:org.mitre.oval:def:460
  • commentMicrosoft Windows XP x64 Edition SP2 is installed
    ovaloval:org.mitre.oval:def:4193
  • commentMicrosoft Windows Server 2003 SP2 (x86) is installed
    ovaloval:org.mitre.oval:def:1935
  • commentMicrosoft Windows Server 2003 SP2 (x64) is installed
    ovaloval:org.mitre.oval:def:2161
  • commentMicrosoft Windows Server 2003 (ia64) SP2 is installed
    ovaloval:org.mitre.oval:def:1442
  • commentMicrosoft IIS 6.0 is installed
    ovaloval:org.mitre.oval:def:227
descriptionThe WebDAV extension in Microsoft Internet Information Services (IIS) 5.1 and 6.0 allows remote attackers to bypass URI-based protection mechanisms, and list folders or read, create, or modify files, via a %c0%af (Unicode / character) at an arbitrary position in the URI, as demonstrated by inserting %c0%af into a "/protected/" initial pathname component to bypass the password protection on the protected\ folder, aka "IIS 5.1 and 6.0 WebDAV Authentication Bypass Vulnerability," a different vulnerability than CVE-2009-1122.
familywindows
idoval:org.mitre.oval:def:6029
statusaccepted
submitted2009-05-19T14:00:00
titleIIS 5.1 and 6.0 WebDAV Authentication Bypass Vulnerability
version36