Amazon Linux AMI : samba (ALAS-2021-1469)

##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2021-1469.
##

include('compat.inc');

if (description)
{
  script_id(144992);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/30");

  script_cve_id("CVE-2020-1472", "CVE-2020-14318", "CVE-2020-14323");
  script_xref(name:"ALAS", value:"2021-1469");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2020/09/21");
  script_xref(name:"CISA-NCAS", value:"AA22-011A");
  script_xref(name:"CEA-ID", value:"CEA-2021-0025");
  script_xref(name:"CEA-ID", value:"CEA-2021-0008");
  script_xref(name:"CEA-ID", value:"CEA-2020-0129");
  script_xref(name:"CEA-ID", value:"CEA-2020-0121");
  script_xref(name:"CEA-ID", value:"CEA-2020-0101");
  script_xref(name:"CEA-ID", value:"CEA-2023-0016");

  script_name(english:"Amazon Linux AMI : samba (ALAS-2021-1469)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux AMI host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of samba installed on the remote host is prior to 4.10.16-9.56. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS-2021-1469 advisory.

  - A flaw was found in the way samba handled file and directory permissions. An authenticated user could use
    this flaw to gain access to certain file and directory information which otherwise would be unavailable to
    the attacker. (CVE-2020-14318)

  - A null pointer dereference flaw was found in samba's Winbind service in versions before 4.11.15, before
    4.12.9 and before 4.13.1. A local user could use this flaw to crash the winbind service causing denial of
    service. (CVE-2020-14323)

  - An elevation of privilege vulnerability exists when an attacker establishes a vulnerable Netlogon secure
    channel connection to a domain controller, using the Netlogon Remote Protocol (MS-NRPC), aka 'Netlogon
    Elevation of Privilege Vulnerability'. (CVE-2020-1472)

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:"https://alas.aws.amazon.com/ALAS-2021-1469.html");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/CVE-2020-14318");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/CVE-2020-14323");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/CVE-2020-1472");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update samba' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-1472");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/08/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/01/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/01/14");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ctdb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ctdb-tests");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libsmbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libsmbclient-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libwbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libwbclient-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-client-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-common-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-common-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-krb5-printing");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-pidl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-python");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-python-test");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-test");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-test-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind-krb5-locator");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind-modules");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Amazon Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  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/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "A")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}

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

pkgs = [
    {'reference':'ctdb-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'ctdb-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'ctdb-tests-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'ctdb-tests-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'libsmbclient-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'libsmbclient-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'libsmbclient-devel-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'libsmbclient-devel-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'libwbclient-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'libwbclient-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'libwbclient-devel-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'libwbclient-devel-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-client-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-client-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-client-libs-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-client-libs-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-common-4.10.16-9.56.amzn1', 'release':'ALA'},
    {'reference':'samba-common-libs-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-common-libs-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-common-tools-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-common-tools-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-debuginfo-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-debuginfo-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-devel-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-devel-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-krb5-printing-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-krb5-printing-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-libs-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-libs-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-pidl-4.10.16-9.56.amzn1', 'release':'ALA'},
    {'reference':'samba-python-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-python-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-python-test-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-python-test-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-test-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-test-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-test-libs-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-test-libs-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-winbind-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-winbind-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-winbind-clients-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-winbind-clients-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-winbind-krb5-locator-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-winbind-krb5-locator-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'},
    {'reference':'samba-winbind-modules-4.10.16-9.56.amzn1', 'cpu':'i686', 'release':'ALA'},
    {'reference':'samba-winbind-modules-4.10.16-9.56.amzn1', 'cpu':'x86_64', 'release':'ALA'}
];

flag = 0;
foreach package_array ( pkgs ) {
  reference = NULL;
  release = NULL;
  cpu = NULL;
  el_string = NULL;
  rpm_spec_vers_cmp = NULL;
  allowmaj = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) release = package_array['release'];
  if (!empty_or_null(package_array['cpu'])) cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (reference && release) {
    if (rpm_check(release:release, cpu:cpu, reference:reference, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) 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, "ctdb / ctdb-tests / libsmbclient / etc");
}