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nessusThis script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.FEDORA_2021-8D52A8A999.NASL
HistoryMar 30, 2021 - 12:00 a.m.

Fedora 33 : rpm (2021-8d52a8a999)

2021-03-3000:00:00
This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
23
fedora 33
rpm
vulnerabilities
signature check
attack
rpm database corruption
execute code
cve-2021-20271

CVSS2

5.1

Attack Vector

NETWORK

Attack Complexity

HIGH

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

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

CVSS3

7

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

EPSS

0.002

Percentile

61.2%

The remote Fedora 33 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2021-8d52a8a999 advisory.

  • A flaw was found in RPM’s signature check functionality when reading a package file. This flaw allows an attacker who can convince a victim to install a seemingly verifiable package, whose signature header was modified, to cause RPM database corruption and execute code. The highest threat from this vulnerability is to data integrity, confidentiality, and system availability. (CVE-2021-20271)

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

##
# (C) Tenable Network Security, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2021-8d52a8a999
#

include('compat.inc');

if (description)
{
  script_id(148228);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/01/21");

  script_cve_id("CVE-2021-3421", "CVE-2021-20266", "CVE-2021-20271");
  script_xref(name:"FEDORA", value:"2021-8d52a8a999");

  script_name(english:"Fedora 33 : rpm (2021-8d52a8a999)");

  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 33 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2021-8d52a8a999 advisory.

  - A flaw was found in RPM's signature check functionality when reading a package file. This flaw allows an
    attacker who can convince a victim to install a seemingly verifiable package, whose signature header was
    modified, to cause RPM database corruption and execute code. The highest threat from this vulnerability is
    to data integrity, confidentiality, and system availability. (CVE-2021-20271)

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-2021-8d52a8a999");
  script_set_attribute(attribute:"solution", value:
"Update the affected rpm package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/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:H/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-20271");

  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:"2021/03/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/03/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/03/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:33");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:rpm");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/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:"^33([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 33', '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':'rpm-4.16.1.3-1.fc33', 'release':'FC33', '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_WARNING,
      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, 'rpm');
}

CVSS2

5.1

Attack Vector

NETWORK

Attack Complexity

HIGH

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

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

CVSS3

7

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

EPSS

0.002

Percentile

61.2%