RHEL 8 : libssh2 (Unpatched Vulnerability)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory libssh2. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(199738);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/07/16");

  script_cve_id(
    "CVE-2019-3858",
    "CVE-2019-3859",
    "CVE-2019-3860",
    "CVE-2019-3861",
    "CVE-2019-3862",
    "CVE-2019-13115",
    "CVE-2019-17498"
  );

  script_name(english:"RHEL 8 : libssh2 (Unpatched Vulnerability)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat 8 host is affected by multiple vulnerabilities that will not be patched.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 8 host has one or more packages installed that are affected by multiple
vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - libssh2: Out-of-bounds memory comparison with specially crafted message channel request (CVE-2019-3862)

  - In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an
    integer overflow that could lead to an out-of-bounds read in the way packets are read from the server. A
    remote attacker who compromises a SSH server may be able to disclose sensitive information or cause a
    denial of service condition on the client system when a user connects to the server. This is related to an
    _libssh2_check_length mistake, and is different from the various issues fixed in 1.8.1, such as
    CVE-2019-3855. (CVE-2019-13115)

  - In libssh2 v1.9.0 and earlier versions, the SSH_MSG_DISCONNECT logic in packet.c has an integer overflow
    in a bounds check, enabling an attacker to specify an arbitrary (out-of-bounds) offset for a subsequent
    memory read. A crafted SSH server may be able to disclose sensitive information or cause a denial of
    service condition on the client system when a user connects to the server. (CVE-2019-17498)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package
is installed.");
  script_set_attribute(attribute:"solution", value:
"The vendor has acknowledged the vulnerabilities but no solution has been provided. Refer to the vendor for remediation
guidance.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/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:L/PR:N/UI:N/S:U/C:H/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-3862");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/03/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/06/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libssh2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

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

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

  exit(0);
}


include('rpm.inc');
include('rhel.inc');

if (!get_kb_item("global_settings/vendor_unpatched"))
exit(0, "Unpatched Vulnerabilities Detection not active.");

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

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var 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 && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var appstreams = {
  'virt:8.0': [
    {
      'pkgs': [
        {'reference':'libssh2', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'libssh2', 'cves':['CVE-2019-17498']}
      ]
    }
  ],
  'virt:8.0.0': [
    {
      'pkgs': [
        {'reference':'libssh2', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'libssh2', 'cves':['CVE-2019-3858', 'CVE-2019-3859', 'CVE-2019-3860', 'CVE-2019-3861', 'CVE-2019-3862', 'CVE-2019-13115']},
        {'reference':'libssh2', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'libssh2', 'cves':['CVE-2019-3859', 'CVE-2019-3860']}
      ]
    }
  ],
  'virt:rhel': [
    {
      'pkgs': [
        {'reference':'libssh2', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'libssh2', 'cves':['CVE-2019-3859', 'CVE-2019-3860']},
        {'reference':'libssh2', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'libssh2', 'cves':['CVE-2019-3859', 'CVE-2019-3860']}
      ]
    }
  ]
};


var flag = 0;
var appstreams_found = 0;
foreach var module (keys(appstreams)) {
  var appstream = NULL;
  var appstream_name = NULL;
  var appstream_version = NULL;
  var appstream_split = split(module, sep:':', keep:FALSE);
  if (!empty_or_null(appstream_split)) {
    appstream_name = appstream_split[0];
    appstream_version = appstream_split[1];
    if (!empty_or_null(appstream_name)) appstream = get_one_kb_item('Host/RedHat/appstream/' + appstream_name);
  }
  if (!empty_or_null(appstream) && appstream_version == appstream || appstream_name == 'all') {
    appstreams_found++;
    foreach var module_array ( appstreams[module] ) {
      var repo_relative_urls = NULL;
      var enterprise_linux_flag = rhel_repo_urls_has_content_dist_rhel(repo_urls:repo_relative_urls);
      foreach var package_array ( module_array['pkgs'] ) {
        var unpatched_pkg = NULL;
        var _release = NULL;
        var sp = NULL;
        var el_string = NULL;
        var rpm_spec_vers_cmp = NULL;
        var exists_check = NULL;
        var cves = NULL;
        if (!empty_or_null(package_array['unpatched_pkg'])) unpatched_pkg = package_array['unpatched_pkg'];
        if (!empty_or_null(package_array['release'])) _release = 'RHEL' + package_array['release'];
        if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
        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['exists_check'])) exists_check = package_array['exists_check'];
        if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
        if (unpatched_pkg &&
            _release &&
            (!exists_check || rpm_exists(release:_release, rpm:exists_check)) &&
            unpatched_package_exists(release:_release, package:unpatched_pkg, cves: cves)) flag++;
      }
    }
  }
}

if (!appstreams_found) audit(AUDIT_PACKAGE_NOT_INSTALLED, 'Module virt:8.0 / virt:8.0.0 / virt:rhel');

if (flag)
{
  var extra = NULL;
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : unpatched_packages_report()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libssh2');
}