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nessusThis script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.FEDORA_2023-5FA5CA2043.NASL
HistoryMay 28, 2023 - 12:00 a.m.

Fedora 37 : libssh (2023-5fa5ca2043)

2023-05-2800:00:00
This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
14
fedora 37
libssh
vulnerability
null pointer dereference
authentication bypass
denial of service
memory allocation
cryptographic verification

7.7 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

48.7%

The remote Fedora 37 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-5fa5ca2043 advisory.

  • A NULL pointer dereference was found In libssh during re-keying with algorithm guessing. This issue may allow an authenticated client to cause a denial of service. (CVE-2023-1667)

  • A vulnerability was found in libssh, where the authentication check of the connecting client can be bypassed in thepki_verify_data_signature function in memory allocation problems. This issue may happen if there is insufficient memory or the memory usage is limited. The problem is caused by the return value rc, which is initialized to SSH_ERROR and later rewritten to save the return value of the function call pki_key_check_hash_compatible. The value of the variable is not changed between this point and the cryptographic verification. Therefore any error between them calls goto error returning SSH_OK.
    (CVE-2023-2283)

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 descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2023-5fa5ca2043
#

include('compat.inc');

if (description)
{
  script_id(176439);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/22");

  script_cve_id("CVE-2023-1667", "CVE-2023-2283");
  script_xref(name:"FEDORA", value:"2023-5fa5ca2043");
  script_xref(name:"IAVA", value:"2023-A-0517-S");

  script_name(english:"Fedora 37 : libssh (2023-5fa5ca2043)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Fedora 37 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2023-5fa5ca2043 advisory.

  - A NULL pointer dereference was found In libssh during re-keying with algorithm guessing. This issue may
    allow an authenticated client to cause a denial of service. (CVE-2023-1667)

  - A vulnerability was found in libssh, where the authentication check of the connecting client can be
    bypassed in the`pki_verify_data_signature` function in memory allocation problems. This issue may happen
    if there is insufficient memory or the memory usage is limited. The problem is caused by the return value
    `rc,` which is initialized to SSH_ERROR and later rewritten to save the return value of the function call
    `pki_key_check_hash_compatible.` The value of the variable is not changed between this point and the
    cryptographic verification. Therefore any error between them calls `goto error` returning SSH_OK.
    (CVE-2023-2283)

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://bodhi.fedoraproject.org/updates/FEDORA-2023-5fa5ca2043");
  script_set_attribute(attribute:"solution", value:
"Update the affected libssh package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/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:L/I:L/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-2023-2283");

  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:"2023/05/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/05/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/05/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:37");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:libssh");
  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:"Fedora Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 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/RedHat/release", "Host/RedHat/rpm-list");

  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/RedHat/release');
if (isnull(os_release) || 'Fedora' >!< os_release) audit(AUDIT_OS_NOT, 'Fedora');
var os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
os_ver = os_ver[1];
if (! preg(pattern:"^37([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 37', 'Fedora ' + 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) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Fedora', cpu);

var pkgs = [
    {'reference':'libssh-0.10.5-1.fc37', 'release':'FC37', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach 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 = 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');
}
VendorProductVersionCPE
fedoraprojectfedora37cpe:/o:fedoraproject:fedora:37
fedoraprojectfedoralibsshp-cpe:/a:fedoraproject:fedora:libssh