NewStart CGSL MAIN 4.05 : samba4 Multiple Vulnerabilities (NS-SA-2019-0100)

2019-08-12T00:00:00
ID NEWSTART_CGSL_NS-SA-2019-0100_SAMBA4.NASL
Type nessus
Reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-06-02T00:00:00

Description

The remote NewStart CGSL host, running version MAIN 4.05, has samba4 packages installed that are affected by multiple vulnerabilities:

  • A flaw was found in the way Samba handled PAC (Privilege Attribute Certificate) checksums. A remote, authenticated attacker could use this flaw to crash the winbindd process. (CVE-2016-2126)

  • It was found that Samba always requested forwardable tickets when using Kerberos authentication. A service to which Samba authenticated using Kerberos could subsequently use the ticket to impersonate Samba to other services or domain users. (CVE-2016-2125)

  • A remote code execution flaw was found in Samba. A malicious authenticated samba client, having write access to the samba share, could use this flaw to execute arbitrary code as root. (CVE-2017-7494)

Note that Nessus has not tested for this issue but has instead relied only on the application

                                        
                                            #
# (C) Tenable Network Security, Inc.
#

# The descriptive text and package checks in this plugin were
# extracted from ZTE advisory NS-SA-2019-0100. The text
# itself is copyright (C) ZTE, Inc.

include("compat.inc");

if (description)
{
  script_id(127327);
  script_version("1.3");
  script_cvs_date("Date: 2019/09/24 11:01:33");

  script_cve_id("CVE-2016-2125", "CVE-2016-2126", "CVE-2017-7494");

  script_name(english:"NewStart CGSL MAIN 4.05 : samba4 Multiple Vulnerabilities (NS-SA-2019-0100)");

  script_set_attribute(attribute:"synopsis", value:
"The remote machine is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote NewStart CGSL host, running version MAIN 4.05, has samba4 packages installed that are affected by multiple
vulnerabilities:

  - A flaw was found in the way Samba handled PAC (Privilege
    Attribute Certificate) checksums. A remote,
    authenticated attacker could use this flaw to crash the
    winbindd process. (CVE-2016-2126)

  - It was found that Samba always requested forwardable
    tickets when using Kerberos authentication. A service to
    which Samba authenticated using Kerberos could
    subsequently use the ticket to impersonate Samba to
    other services or domain users. (CVE-2016-2125)

  - A remote code execution flaw was found in Samba. A
    malicious authenticated samba client, having write
    access to the samba share, could use this flaw to
    execute arbitrary code as root. (CVE-2017-7494)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/notice/NS-SA-2019-0100");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL samba4 packages. Note that updated packages may not be available yet. Please contact ZTE for
more information.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-7494");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Samba is_known_pipename() Arbitrary Module Load');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
  script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
  script_set_attribute(attribute:"canvas_package", value:'CANVAS');


  script_set_attribute(attribute:"vuln_publication_date", value:"2017/05/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/07/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/08/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"NewStart CGSL Local Security Checks");

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

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/ZTE-CGSL/release", "Host/ZTE-CGSL/rpm-list", "Host/cpu");

  exit(0);
}

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

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

release = get_kb_item("Host/ZTE-CGSL/release");
if (isnull(release) || release !~ "^CGSL (MAIN|CORE)") audit(AUDIT_OS_NOT, "NewStart Carrier Grade Server Linux");

if (release !~ "CGSL MAIN 4.05")
  audit(AUDIT_OS_NOT, 'NewStart CGSL MAIN 4.05');

if (!get_kb_item("Host/ZTE-CGSL/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "NewStart Carrier Grade Server Linux", cpu);

flag = 0;

pkgs = {
  "CGSL MAIN 4.05": [
    "samba4-libs-4.2.10-10.el6_9"
  ]
};
pkg_list = pkgs[release];

foreach (pkg in pkg_list)
  if (rpm_check(release:"ZTE " + release, reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "samba4");
}