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nessusThis script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.CENTOS8_RHSA-2024-3233.NASL
HistoryMay 22, 2024 - 12:00 a.m.

CentOS 8 : libssh (CESA-2024:3233)

2024-05-2200:00:00
This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
4
libssh vulnerability
proxycommand exploit
proxyjump exploit
hostname syntax
malicious code injection
message digest
crypto backends
low-memory failure
null dereference
application version scanner

5.3 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

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

6.8 Medium

AI Score

Confidence

Low

0.001 Low

EPSS

Percentile

35.1%

The remote CentOS Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the CESA-2024:3233 advisory.

  • A flaw was found in libssh. By utilizing the ProxyCommand or ProxyJump feature, users can exploit unchecked hostname syntax on the client. This issue may allow an attacker to inject malicious code into the command of the features mentioned through the hostname parameter. (CVE-2023-6004)

  • A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by different supported crypto backends. The return values from these were not properly checked, which could cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures, terminating the connection. (CVE-2023-6918)

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

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The package checks in this plugin were extracted from
# Red Hat Security Advisory RHSA-2024:3233. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(197683);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/22");

  script_cve_id("CVE-2023-6004", "CVE-2023-6918");
  script_xref(name:"IAVA", value:"2023-A-0703");
  script_xref(name:"RHSA", value:"2024:3233");

  script_name(english:"CentOS 8 : libssh (CESA-2024:3233)");

  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-2024:3233 advisory.

  - A flaw was found in libssh. By utilizing the ProxyCommand or ProxyJump feature, users can exploit
    unchecked hostname syntax on the client. This issue may allow an attacker to inject malicious code into
    the command of the features mentioned through the hostname parameter. (CVE-2023-6004)

  - A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by
    different supported crypto backends. The return values from these were not properly checked, which could
    cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as
    an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures,
    terminating the connection. (CVE-2023-6918)

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:"https://access.redhat.com/errata/RHSA-2024:3233");
  script_set_attribute(attribute:"solution", value:
"Update the affected libssh, libssh-config and / or libssh-devel packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-6004");

  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:"2023/12/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/05/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/05/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8-stream");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:libssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:libssh-config");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:libssh-devel");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"II");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CentOS 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");
  script_require_keys("Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/rpm-list", "Host/cpu");

  exit(0);
}


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

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

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, 'CentOS', cpu);

var pkgs = [
    {'reference':'libssh-0.9.6-14.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libssh-0.9.6-14.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libssh-config-0.9.6-14.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libssh-config-0.9.6-14.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libssh-devel-0.9.6-14.el8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libssh-devel-0.9.6-14.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var 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
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libssh / libssh-config / libssh-devel');
}
VendorProductVersionCPE
centoscentos8-streamcpe:/o:centos:centos:8-stream
centoscentoslibssh-develp-cpe:/a:centos:centos:libssh-devel
centoscentoslibssh-configp-cpe:/a:centos:centos:libssh-config
centoscentoslibsshp-cpe:/a:centos:centos:libssh

5.3 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

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

6.8 Medium

AI Score

Confidence

Low

0.001 Low

EPSS

Percentile

35.1%