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nessusThis script is Copyright (C) 2022 and is owned by Tenable, Inc. or an Affiliate thereof.NEWSTART_CGSL_NS-SA-2022-0088_LIBGCRYPT.NASL
HistoryNov 15, 2022 - 12:00 a.m.

NewStart CGSL MAIN 6.02 : libgcrypt Vulnerability (NS-SA-2022-0088)

2022-11-1500:00:00
This script is Copyright (C) 2022 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
16
newstart cgsl
libgcrypt
vulnerability
elgamal encryption
side-channel attack
mpi_powm
window size
openpgp
cve-2021-33560
nessus
scanner

CVSS2

5

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS3

7.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

0.002

Percentile

61.1%

The remote NewStart CGSL host, running version MAIN 6.02, has libgcrypt packages installed that are affected by a vulnerability:

  • Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm, and the window size is not chosen appropriately. This, for example, affects use of ElGamal in OpenPGP. (CVE-2021-33560)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from ZTE advisory NS-SA-2022-0088. The text
# itself is copyright (C) ZTE, Inc.
##

include('compat.inc');

if (description)
{
  script_id(167481);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/11/15");

  script_cve_id("CVE-2021-33560");

  script_name(english:"NewStart CGSL MAIN 6.02 : libgcrypt Vulnerability (NS-SA-2022-0088)");

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

  - Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent
    blinding to address a side-channel attack against mpi_powm, and the window size is not chosen
    appropriately. This, for example, affects use of ElGamal in OpenPGP. (CVE-2021-33560)

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-2022-0088");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/info/CVE-2021-33560");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL libgcrypt 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:U/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:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-33560");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/06/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/11/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/11/15");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libgcrypt");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libgcrypt-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 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 os_release = get_kb_item('Host/ZTE-CGSL/release');
if (isnull(os_release) || os_release !~ "^CGSL (MAIN|CORE)") audit(AUDIT_OS_NOT, 'NewStart Carrier Grade Server Linux');

if (os_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': [
    'libgcrypt-1.8.5-6.el8',
    'libgcrypt-devel-1.8.5-6.el8'
  ]
};
var pkg_list = pkgs[os_release];

foreach (pkg in pkg_list)
  if (rpm_check(release:'ZTE ' + os_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, 'libgcrypt');
}

CVSS2

5

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS3

7.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

0.002

Percentile

61.1%