CentOS 8 : openssh (CESA-2019:3702)

##
# (C) Tenable Network Security, Inc.
#
# The package checks in this plugin were extracted from
# Red Hat Security Advisory RHSA-2019:3702. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(145578);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/05/11");

  script_cve_id("CVE-2018-20685", "CVE-2019-6109", "CVE-2019-6111");
  script_bugtraq_id(106531, 106741, 106843);
  script_xref(name:"RHSA", value:"2019:3702");

  script_name(english:"CentOS 8 : openssh (CESA-2019:3702)");

  script_set_attribute(attribute:"synopsis", value:
"The remote CentOS host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote CentOS Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the
CESA-2019:3702 advisory.

  - openssh: scp client improper directory name validation (CVE-2018-20685)

  - openssh: Missing character encoding in progress display allows for spoofing of scp client output
    (CVE-2019-6109)

  - openssh: Improper validation of object names allows malicious server to overwrite files via scp client
    (CVE-2019-6111)

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://access.redhat.com/errata/RHSA-2019:3702");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-6111");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2019-6109");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/01/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/11/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/01/29");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssh-askpass");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssh-cavs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssh-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssh-keycat");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssh-ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssh-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:pam_ssh_agent_auth");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('audit.inc');
include('global_settings.inc');
include('misc_func.inc');
include('rpm.inc');
include('rhel.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item('Host/CentOS/release');
if (isnull(release) || 'CentOS' >!< release) audit(AUDIT_OS_NOT, 'CentOS');
os_ver = pregmatch(pattern: "CentOS(?: Stream)?(?: Linux)? release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'CentOS');
os_ver = os_ver[1];
if ('CentOS Stream' >< release) audit(AUDIT_OS_NOT, 'CentOS 8.x', 'CentOS Stream ' + os_ver);
if (!rhel_check_release(operator: 'ge', os_version: os_ver, rhel_version: '8')) audit(AUDIT_OS_NOT, 'CentOS 8.x', 'CentOS ' + os_ver);

if (!get_kb_item('Host/CentOS/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$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'CentOS', cpu);

pkgs = [
    {'reference':'openssh-8.0p1-3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-8.0p1-3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-askpass-8.0p1-3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-askpass-8.0p1-3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-cavs-8.0p1-3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-cavs-8.0p1-3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-clients-8.0p1-3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-clients-8.0p1-3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-keycat-8.0p1-3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-keycat-8.0p1-3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-ldap-8.0p1-3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-ldap-8.0p1-3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-server-8.0p1-3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'openssh-server-8.0p1-3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'pam_ssh_agent_auth-0.10.3-7.3.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'pam_ssh_agent_auth-0.10.3-7.3.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE}
];

flag = 0;
foreach package_array ( pkgs ) {
  reference = NULL;
  release = NULL;
  sp = NULL;
  cpu = NULL;
  el_string = NULL;
  rpm_spec_vers_cmp = NULL;
  epoch = NULL;
  allowmaj = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) release = 'CentOS-' + package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  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['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (reference && release) {
    if (rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      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, 'openssh / openssh-askpass / openssh-cavs / openssh-clients / etc');
}