Vulnerabilities > CVE-2016-7251 - Cross-site Scripting vulnerability in Microsoft SQL Server 2016

047910
CVSS 4.3 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
PARTIAL
Availability impact
NONE
network
microsoft
CWE-79
nessus
NVD
Published: 2016-11-10
Updated: 2018-10-12

Summary

Cross-site scripting (XSS) vulnerability in the MDS API in Microsoft SQL Server 2016 allows remote attackers to inject arbitrary web script or HTML via an unspecified parameter, aka "MDS API XSS Vulnerability."

Vulnerable Configurations

Part Description Count
Application
Microsoft
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Embedding Scripts in Non-Script Elements
    This attack is a form of Cross-Site Scripting (XSS) where malicious scripts are embedded in elements that are not expected to host scripts such as image tags (<img>), comments in XML documents (< !-CDATA->), etc. These tags may not be subject to the same input validation, output validation, and other content filtering and checking routines, so this can create an opportunity for an attacker to tunnel through the application's elements and launch a XSS attack through other elements. As with all remote attacks, it is important to differentiate the ability to launch an attack (such as probing an internal network for unpatched servers) and the ability of the remote attacker to collect and interpret the output of said attack.
  • Embedding Scripts within Scripts
    An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute scripts. The attacker leverages this capability to execute scripts to execute his/her own script by embedding it within other scripts that the target software is likely to execute. The attacker must have the ability to inject script into script that is likely to be executed. If this is done, then the attacker can potentially launch a variety of probes and attacks against the web server's local environment, in many cases the so-called DMZ, back end resources the web server can communicate with, and other hosts. With the proliferation of intermediaries, such as Web App Firewalls, network devices, and even printers having JVMs and Web servers, there are many locales where an attacker can inject malicious scripts. Since this attack pattern defines scripts within scripts, there are likely privileges to execute said attack on the host. Of course, these attacks are not solely limited to the server side, client side scripts like Ajax and client side JavaScript can contain malicious scripts as well. In general all that is required is for there to be sufficient privileges to execute a script, but not protected against writing.
  • Cross-Site Scripting in Error Pages
    An attacker distributes a link (or possibly some other query structure) with a request to a third party web server that is malformed and also contains a block of exploit code in order to have the exploit become live code in the resulting error page. When the third party web server receives the crafted request and notes the error it then creates an error message that echoes the malformed message, including the exploit. Doing this converts the exploit portion of the message into to valid language elements that are executed by the viewing browser. When a victim executes the query provided by the attacker the infected error message error message is returned including the exploit code which then runs in the victim's browser. XSS can result in execution of code as well as data leakage (e.g. session cookies can be sent to the attacker). This type of attack is especially dangerous since the exploit appears to come from the third party web server, who the victim may trust and hence be more vulnerable to deception.
  • Cross-Site Scripting Using Alternate Syntax
    The attacker uses alternate forms of keywords or commands that result in the same action as the primary form but which may not be caught by filters. For example, many keywords are processed in a case insensitive manner. If the site's web filtering algorithm does not convert all tags into a consistent case before the comparison with forbidden keywords it is possible to bypass filters (e.g., incomplete black lists) by using an alternate case structure. For example, the "script" tag using the alternate forms of "Script" or "ScRiPt" may bypass filters where "script" is the only form tested. Other variants using different syntax representations are also possible as well as using pollution meta-characters or entities that are eventually ignored by the rendering engine. The attack can result in the execution of otherwise prohibited functionality.

Msbulletin

bulletin_idMS16-136
bulletin_url
date2016-11-08T00:00:00
impactElevation of Privilege
knowledgebase_id3199641
knowledgebase_url
severityImportant
titleSecurity Update for SQL Server

Nessus

  • NASL familyWindows : Microsoft Bulletins
    NASL idSMB_NT_MS16-136.NASL
    descriptionThe remote Microsoft SQL Server is missing a security update. It is, therefore, affected by multiple vulnerabilities : - Multiple elevation of privilege vulnerabilities exist in the SQL RDBMS Engine due to improper handling of pointer casting. An authenticated, remote attacker can exploit these to gain elevated privileges. (CVE-2016-7249, CVE-2016-7250, CVE-2016-7254) - A cross-site scripting (XSS) vulnerability exists in the SQL server MDS API due to improper validation of a request parameter on the SQL server site. An unauthenticated, remote attacker can exploit this, via a specially crafted request, to execute arbitrary code in the user
    last seen2020-06-01
    modified2020-06-02
    plugin id94637
    published2016-11-08
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/94637
    titleMS16-136: Security Update for SQL Server (3199641)
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(94637);
  script_version("1.12");
  script_cvs_date("Date: 2019/11/14");

  script_cve_id(
    "CVE-2016-7249",
    "CVE-2016-7250",
    "CVE-2016-7251",
    "CVE-2016-7252",
    "CVE-2016-7253",
    "CVE-2016-7254"
  );
  script_bugtraq_id(
    94037,
    94043,
    94050,
    94056,
    94060,
    94061
  );
  script_xref(name:"MSFT", value:"MS16-136");
  script_xref(name:"MSKB", value:"3194714");
  script_xref(name:"MSKB", value:"3194716");
  script_xref(name:"MSKB", value:"3194717");
  script_xref(name:"MSKB", value:"3194718");
  script_xref(name:"MSKB", value:"3194719");
  script_xref(name:"MSKB", value:"3194720");
  script_xref(name:"MSKB", value:"3194721");
  script_xref(name:"MSKB", value:"3194722");
  script_xref(name:"MSKB", value:"3194724");
  script_xref(name:"MSKB", value:"3194725");

  script_name(english:"MS16-136: Security Update for SQL Server (3199641)");
  script_summary(english:"Determines the version of the SQL Server.");

  script_set_attribute(attribute:"synopsis", value:
"The remote SQL server is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote Microsoft SQL Server is missing a security update. It is,
therefore, affected by multiple vulnerabilities :

  - Multiple elevation of privilege vulnerabilities exist
    in the SQL RDBMS Engine due to improper handling of
    pointer casting. An authenticated, remote attacker can
    exploit these to gain elevated privileges.
    (CVE-2016-7249, CVE-2016-7250, CVE-2016-7254)

  - A cross-site scripting (XSS) vulnerability exists in
    the SQL server MDS API due to improper validation of a
    request parameter on the SQL server site. An
    unauthenticated, remote attacker can exploit this, via
    a specially crafted request, to execute arbitrary code
    in the user's browser session. (CVE-2016-7251)

  - An information disclosure vulnerability exists in
    Microsoft SQL Analysis Services due to improper
    validation of the FILESTREAM path. An authenticated,
    remote attacker can exploit this to disclose sensitive
    database and file information. (CVE-2016-7252)

  - An elevation of privilege vulnerability exists in the
    Microsoft SQL Server Engine due to improper checking by
    the SQL Server Agent of ACLs on atxcore.dll. An
    authenticated, remote attacker can exploit this to gain
    elevated privileges. (CVE-2016-7253)");
  # https://docs.microsoft.com/en-us/security-updates/SecurityBulletins/2016/ms16-136
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7fef1e99");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released a set of patches for SQL Server 2012, 2014, and
2016.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-7254");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/11/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/11/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/11/08");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:sql_server");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows : Microsoft Bulletins");

  script_copyright(english:"This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("smb_hotfixes.nasl", "mssql_version.nasl", "smb_enum_services.nasl", "ms_bulletin_checks_possible.nasl");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, 1433, "Services/mssql", "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 = 'MS16-136';
kbs = make_list(
  "3194714",
  "3194716",
  "3194717",
  "3194718",
  "3194719",
  "3194720",
  "3194721",
  "3194722",
  "3194724",
  "3194725"
);

if (get_kb_item("Host/patch_management_checks")) hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_WARNING);

get_kb_item_or_exit("SMB/Registry/Enumerated");
get_kb_item_or_exit("SMB/WindowsVersion", exit_code:1);

ver_list = get_kb_list("mssql/installs/*/SQLVersion");

if (isnull(ver_list)) audit(AUDIT_NOT_INST, "Microsoft SQL Server");

# Database Services Core Instance
foreach item (keys(ver_list))
{
  item -= 'mssql/installs/';
  item -= '/SQLVersion';
  sqlpath = item;

  share = hotfix_path2share(path:sqlpath);
  if (!is_accessible_share(share:share)) continue;

  version = get_kb_item("mssql/installs/" + sqlpath + "/SQLVersion");

  # continue if not SQL Server 2012, 2014, or 2016
  if (version !~ "^11\.0\." && version !~ "^12\.0\." && version !~ "^13\.0\.") continue;

  sqltype = get_kb_item("mssql/installs/" + sqlpath + "/edition_type");
  if (isnull(sqltype)) sqltype = get_kb_item("mssql/installs/" + sqlpath + "/edition");

  if (
    sqlpath &&
    # 2012 SP2 GDR
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2011.110.5388.0", min_version:"2011.110.5058.0", bulletin:bulletin, kb:'3194719') ||
    # 2012 SP2 CU
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2011.110.5676.0", min_version:"2011.110.5500.0", bulletin:bulletin, kb:'3194725') ||
    # 2012 SP3 GDR
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2011.110.6248.0", min_version:"2011.110.6020.0", bulletin:bulletin, kb:'3194721') ||
    # 2012 SP3 CU
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2011.110.6567.0", min_version:"2011.110.6300.0", bulletin:bulletin, kb:'3194724') ||
    # 2014 SP1 GDR
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2014.120.4232.0", min_version:"2014.120.4100.0", bulletin:bulletin, kb:'3194720') ||
    # 2014 SP1 CU
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2014.120.4487.0", min_version:"2014.120.4400.0", bulletin:bulletin, kb:'3194722') ||
    # 2014 SP2 GDR
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2014.120.5203.0", min_version:"2014.120.5000.0", bulletin:bulletin, kb:'3194714') ||
    # 2014 SP2 CU
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2014.120.5532.0", min_version:"2014.120.5400.0", bulletin:bulletin, kb:'3194718') ||
    # 2016 GDR
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2015.130.1722.0", min_version:"2015.130.1601.5", bulletin:bulletin, kb:'3194716') ||
    # 2016 CU
    hotfix_is_vulnerable(path:sqlpath, file:"sqlservr.exe", version:"2015.130.2186.6", min_version:"2015.130.2100.0", bulletin:bulletin, kb:'3194717')
  )
  {
    vuln++;
  }
}
hotfix_check_fversion_end();

if (vuln)
{
  set_kb_item(name:'www/0/XSS', value:TRUE); # CVE-2016-7251
  set_kb_item(name:"SMB/Missing/"+bulletin, value:TRUE);
  hotfix_security_warning();
  exit(0);
}
audit(AUDIT_HOST_NOT, 'affected');
  • NASL familyWindows
    NASL idSMB_KB3199641.NASL
    descriptionThe remote Microsoft SQL Server is missing a security update. It is, therefore, affected by multiple vulnerabilities : - Multiple elevation of privilege vulnerabilities exist in the SQL RDBMS Engine due to improper handling of pointer casting. An authenticated, remote attacker can exploit these to gain elevated privileges. (CVE-2016-7249, CVE-2016-7250, CVE-2016-7254) - A cross-site scripting (XSS) vulnerability exists in the SQL server MDS API due to improper validation of a request parameter on the SQL server site. An unauthenticated, remote attacker can exploit this, via a specially crafted request, to execute arbitrary code in the user
    last seen2020-06-01
    modified2020-06-02
    plugin id122484
    published2019-02-28
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/122484
    titleMS16-136: Security Update for SQL Server (3199641) (uncredentialed check)
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(122484);
  script_version("1.2");
  script_cvs_date("Date: 2019/10/31 15:18:52");

  script_cve_id(
    "CVE-2016-7249",
    "CVE-2016-7250",
    "CVE-2016-7251",
    "CVE-2016-7252",
    "CVE-2016-7253",
    "CVE-2016-7254"
  );
  script_bugtraq_id(
    94037,
    94043,
    94050,
    94056,
    94060,
    94061
  );
  script_xref(name:"MSFT", value:"MS16-136");
  script_xref(name:"MSKB", value:"3194714");
  script_xref(name:"MSKB", value:"3194716");
  script_xref(name:"MSKB", value:"3194717");
  script_xref(name:"MSKB", value:"3194718");
  script_xref(name:"MSKB", value:"3194719");
  script_xref(name:"MSKB", value:"3194720");
  script_xref(name:"MSKB", value:"3194721");
  script_xref(name:"MSKB", value:"3194722");
  script_xref(name:"MSKB", value:"3194724");
  script_xref(name:"MSKB", value:"3194725");

  script_name(english:"MS16-136: Security Update for SQL Server (3199641) (uncredentialed check)");
  script_summary(english:"Determines the version of the SQL Server.");

  script_set_attribute(attribute:"synopsis", value:
"The remote SQL server is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote Microsoft SQL Server is missing a security update. It is,
therefore, affected by multiple vulnerabilities :

  - Multiple elevation of privilege vulnerabilities exist
    in the SQL RDBMS Engine due to improper handling of
    pointer casting. An authenticated, remote attacker can
    exploit these to gain elevated privileges.
    (CVE-2016-7249, CVE-2016-7250, CVE-2016-7254)

  - A cross-site scripting (XSS) vulnerability exists in
    the SQL server MDS API due to improper validation of a
    request parameter on the SQL server site. An
    unauthenticated, remote attacker can exploit this, via
    a specially crafted request, to execute arbitrary code
    in the user's browser session. (CVE-2016-7251)

  - An information disclosure vulnerability exists in
    Microsoft SQL Analysis Services due to improper
    validation of the FILESTREAM path. An authenticated,
    remote attacker can exploit this to disclose sensitive
    database and file information. (CVE-2016-7252)

  - An elevation of privilege vulnerability exists in the
    Microsoft SQL Server Engine due to improper checking by
    the SQL Server Agent of ACLs on atxcore.dll. An
    authenticated, remote attacker can exploit this to gain
    elevated privileges. (CVE-2016-7253)");
  # https://docs.microsoft.com/en-us/security-updates/SecurityBulletins/2016/ms16-136
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7fef1e99");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released a set of patches for SQL Server 2012, 2014, and
2016.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-7254");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/11/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/11/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/02/28");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:sql_server");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows");

  script_copyright(english:"This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("mssqlserver_detect.nasl");
  script_require_keys("Settings/ParanoidReport");
  script_require_ports(1433, "Services/mssql");

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");

if (report_paranoia < 2)
  audit(AUDIT_PARANOID);

port = get_service(svc:"mssql", exit_on_fail:TRUE);
instance = get_kb_item("MSSQL/" + port + "/InstanceName");
version = get_kb_item_or_exit("MSSQL/" + port + "/Version");

ver = pregmatch(pattern:"^([0-9.]+)([^0-9]|$)", string:version);
if(!isnull(ver) && !isnull(ver[1])) ver = ver[1];

if (
  ver_compare(minver:"11.0.5058.0", ver:ver, fix:"11.0.5388.0", strict:FALSE) < 0 ||  # 2012 SP2 GDR
  ver_compare(minver:"11.0.5500.0", ver:ver, fix:"11.0.5676.0", strict:FALSE) < 0 ||  # 2012 SP2 CU
  ver_compare(minver:"11.0.6020.0", ver:ver, fix:"11.0.6248.0", strict:FALSE) < 0 ||  # 2012 SP3 GDR
  ver_compare(minver:"11.0.6300.0", ver:ver, fix:"11.0.6567.0", strict:FALSE) < 0 ||  # 2012 SP3 CU
  ver_compare(minver:"12.0.4100.0", ver:ver, fix:"12.0.4232.0", strict:FALSE) < 0 ||  # 2014 SP1 GDR
  ver_compare(minver:"12.0.4400.0", ver:ver, fix:"12.0.4487.0", strict:FALSE) < 0 ||  # 2014 SP1 CU
  ver_compare(minver:"12.0.5000.0", ver:ver, fix:"12.0.5203.0", strict:FALSE) < 0 ||  # 2014 SP2 GDR
  ver_compare(minver:"12.0.5400.0", ver:ver, fix:"12.0.5532.0", strict:FALSE) < 0 ||  # 2014 SP2 CU
  ver_compare(minver:"13.0.1601.0", ver:ver, fix:"13.0.1722.0", strict:FALSE) < 0 ||  # 2016 GDR
  ver_compare(minver:"13.0.2100.0", ver:ver, fix:"13.0.2186.0", strict:FALSE) < 0     # 2016 CU
)
{
  report = '';
  if(!empty_or_null(version)) report += '\n  SQL Server Version   : ' + version;
  if(!empty_or_null(instance)) report += '\n  SQL Server Instance  : ' + instance;
  security_report_v4(port:port, extra:report, severity:SECURITY_WARNING);
}
else audit(AUDIT_INST_VER_NOT_VULN, "MSSQL", version);

References