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nessusThis script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.EULEROS_SA-2022-1173.NASL
HistoryFeb 23, 2022 - 12:00 a.m.

EulerOS 2.0 SP3 : libgcrypt (EulerOS-SA-2022-1173)

2022-02-2300:00:00
This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
17
euleros
libgcrypt
security
vulnerabilities
elgamal encryption
side-channel attack
mpi_powm
window size
plaintext recovery
cryptographic libraries
cross-configuration attack
openpgp
cve-2021-33560
cve-2021-40528

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

AI Score

8

Confidence

High

EPSS

0.002

Percentile

61.1%

According to the versions of the libgcrypt packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  • 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)

  • The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver’s public key, the generator defined by the receiver’s public key, and the sender’s ephemeral exponents can lead to a cross-configuration attack against OpenPGP. (CVE-2021-40528)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(158312);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/07");

  script_cve_id("CVE-2021-40528");

  script_name(english:"EulerOS 2.0 SP3 : libgcrypt (EulerOS-SA-2022-1173)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the libgcrypt packages installed, the EulerOS installation on the remote host is affected
by the following vulnerabilities :

  - 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)

  - The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction
    between two cryptographic libraries, a certain dangerous combination of the prime defined by the
    receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral
    exponents can lead to a cross-configuration attack against OpenPGP. (CVE-2021-40528)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security
advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional
issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2022-1173
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?790bbccb");
  script_set_attribute(attribute:"solution", value:
"Update the affected libgcrypt packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-40528");

  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:"2021/06/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/02/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/02/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libgcrypt");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libgcrypt-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei 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/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  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);

var release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP3");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(3)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP3");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP3", "EulerOS UVP " + uvp);

if (!get_kb_item("Host/EulerOS/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$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

var flag = 0;

var pkgs = [
  "libgcrypt-1.5.3-13.1.h5",
  "libgcrypt-devel-1.5.3-13.1.h5"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"3", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_NOTE,
    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

AI Score

8

Confidence

High

EPSS

0.002

Percentile

61.1%