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nessusThis script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.FEDORA_2021-8840CBDCCD.NASL
HistoryJan 27, 2021 - 12:00 a.m.

Fedora 32 : sudo (2021-8840cbdccd)

2021-01-2700:00:00
This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
31
fedora 32
sudo vulnerabilities
privilege escalation
buffer overflow
arbitrary directory
nessus scanner

CVSS2

7.2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

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

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

EPSS

0.961

Percentile

99.5%

The remote Fedora 32 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2021-8840cbdccd advisory.

  • Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root via sudoedit -s and a command-line argument that ends with a single backslash character. (CVE-2021-3156)

  • The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning a sudo_edit.c race condition in replacing a user-controlled directory by a symlink to an arbitrary path. (CVE-2021-23239)

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 70300
##
# (C) Tenable Network Security, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2021-8840cbdccd
#

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

if (description)
{
  script_id(145482);
  script_version("1.11");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/01/18");

  script_cve_id("CVE-2021-3156");
  script_xref(name:"FEDORA", value:"2021-8840cbdccd");
  script_xref(name:"IAVA", value:"2021-A-0053");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/04/27");

  script_name(english:"Fedora 32 : sudo (2021-8840cbdccd)");

  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 32 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2021-8840cbdccd advisory.

  - Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which
    allows privilege escalation to root via sudoedit -s and a command-line argument that ends with a single
    backslash character. (CVE-2021-3156)

  - The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary
    directory-existence tests by winning a sudo_edit.c race condition in replacing a user-controlled directory
    by a symlink to an arbitrary path. (CVE-2021-23239)

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:"https://bodhi.fedoraproject.org/updates/FEDORA-2021-8840cbdccd");
  script_set_attribute(attribute:"solution", value:
"Update the affected sudo package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3156");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Sudo Heap-Based Buffer Overflow');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
  script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
  script_set_attribute(attribute:"canvas_package", value:"CANVAS");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/01/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/01/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/01/27");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:sudo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:32");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2023 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('audit.inc');
include('global_settings.inc');
include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item('Host/RedHat/release');
if (isnull(release) || 'Fedora' >!< release) audit(AUDIT_OS_NOT, 'Fedora');
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
os_ver = os_ver[1];
if (! preg(pattern:"^32([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 32', 'Fedora ' + os_ver);

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

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);

pkgs = [
    {'reference':'sudo-1.9.5p2-1.fc32', 'release':'FC32', 'rpm_spec_vers_cmp':TRUE}
];

flag = 0;
foreach package_array ( pkgs ) {
  reference = NULL;
  release = NULL;
  sp = NULL;
  cpu = NULL;
  el_string = NULL;
  rpm_spec_vers_cmp = NULL;
  epoch = NULL;
  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_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'sudo');
}
VendorProductVersionCPE
fedoraprojectfedorasudop-cpe:/a:fedoraproject:fedora:sudo
fedoraprojectfedora32cpe:/o:fedoraproject:fedora:32

CVSS2

7.2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

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

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

EPSS

0.961

Percentile

99.5%