NewStart CGSL MAIN 6.02 : libvncserver Multiple Vulnerabilities (NS-SA-2022-0048)

##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from ZTE advisory NS-SA-2022-0048. The text
# itself is copyright (C) ZTE, Inc.
##

include('compat.inc');

if (description)
{
  script_id(160737);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/30");

  script_cve_id(
    "CVE-2018-21247",
    "CVE-2019-20839",
    "CVE-2020-14397",
    "CVE-2020-14405",
    "CVE-2020-25708"
  );

  script_name(english:"NewStart CGSL MAIN 6.02 : libvncserver Multiple Vulnerabilities (NS-SA-2022-0048)");

  script_set_attribute(attribute:"synopsis", value:
"The remote NewStart CGSL host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote NewStart CGSL host, running version MAIN 6.02, has libvncserver packages installed that are affected by
multiple vulnerabilities:

  - An issue was discovered in LibVNCServer before 0.9.13. There is an information leak (of uninitialized
    memory contents) in the libvncclient/rfbproto.c ConnectToRFBRepeater function. (CVE-2018-21247)

  - libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.
    (CVE-2019-20839)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rfbregion.c has a NULL pointer
    dereference. (CVE-2020-14397)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncclient/rfbproto.c does not limit TextChat
    size. (CVE-2020-14405)

  - A divide by zero issue was found to occur in libvncserver-0.9.12. A malicious client could use this flaw
    to send a specially crafted message that, when processed by the VNC server, would lead to a floating point
    exception, resulting in a denial of service. (CVE-2020-25708)

Note that Nessus has not tested for these issues 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-2022-0048");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/info/CVE-2018-21247");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/info/CVE-2019-20839");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/info/CVE-2020-14397");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/info/CVE-2020-14405");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/info/CVE-2020-25708");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL libvncserver 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:P/I:N/A:N");
  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:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-21247");

  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:"2020/06/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/05/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/05/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libvncserver");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libvncserver-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libvncserver-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libvncserver-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:zte:cgsl_main:6");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022-2023 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('rpm.inc');

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

var 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 6.02")
  audit(AUDIT_OS_NOT, 'NewStart CGSL MAIN 6.02');

if (!get_kb_item('Host/ZTE-CGSL/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$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'NewStart Carrier Grade Server Linux', cpu);

var flag = 0;

var pkgs = {
  'CGSL MAIN 6.02': [
    'libvncserver-0.9.11-17.el8',
    'libvncserver-debuginfo-0.9.11-17.el8',
    'libvncserver-debugsource-0.9.11-17.el8',
    'libvncserver-devel-0.9.11-17.el8'
  ]
};
var 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_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libvncserver');
}