Vulnerabilities > CVE-2016-7253 - Permissions, Privileges, and Access Controls vulnerability in Microsoft SQL Server 2012/2014

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
microsoft
CWE-264
nessus
NVD
Published: 2016-11-10
Updated: 2018-10-12

Summary

The agent in Microsoft SQL Server 2012 SP2, 2012 SP3, 2014 SP1, 2014 SP2, and 2016 does not properly check the atxcore.dll ACL, which allows remote authenticated users to gain privileges via unspecified vectors, aka "SQL Server Agent Elevation of Privilege Vulnerability."

Vulnerable Configurations

Part Description Count
Application
Microsoft
4

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Blue Boxing
    This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
  • Target Programs with Elevated Privileges
    This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.

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