CVSS3
Attack Vector
ADJACENT
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
79.6%
The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2024:1873 advisory.
The shim package contains a first-stage UEFI boot loader that handles chaining to a trusted full boot loader under secure boot environments.
Security Fix(es):
* shim: RCE in http boot support may lead to Secure Boot bypass (CVE-2023-40547)
* shim: Interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems (CVE-2023-40548)
* shim: Out-of-bounds read printing error messages (CVE-2023-40546)
* shim: Out-of-bounds read in verify_buffer_authenticode() malformed PE file (CVE-2023-40549)
* shim: Out-of-bound read in verify_buffer_sbat() (CVE-2023-40550)
* shim: out of bounds read when parsing MZ binaries (CVE-2023-40551)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.
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 Red Hat Security Advisory RHSA-2024:1873. The text
# itself is copyright (C) Red Hat, Inc.
##
include('compat.inc');
if (description)
{
script_id(193477);
script_version("1.1");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/06/03");
script_cve_id(
"CVE-2023-40546",
"CVE-2023-40547",
"CVE-2023-40548",
"CVE-2023-40549",
"CVE-2023-40550",
"CVE-2023-40551"
);
script_xref(name:"RHSA", value:"2024:1873");
script_name(english:"RHEL 8 : shim (RHSA-2024:1873)");
script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing one or more security updates for shim.");
script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as
referenced in the RHSA-2024:1873 advisory.
The shim package contains a first-stage UEFI boot loader that handles chaining
to a trusted full boot loader under secure boot environments.
Security Fix(es):
* shim: RCE in http boot support may lead to Secure Boot bypass (CVE-2023-40547)
* shim: Interger overflow leads to heap buffer overflow in verify_sbat_section
on 32-bits systems (CVE-2023-40548)
* shim: Out-of-bounds read printing error messages (CVE-2023-40546)
* shim: Out-of-bounds read in verify_buffer_authenticode() malformed PE file
(CVE-2023-40549)
* shim: Out-of-bound read in verify_buffer_sbat() (CVE-2023-40550)
* shim: out of bounds read when parsing MZ binaries (CVE-2023-40551)
For more details about the security issue(s), including the impact, a CVSS
score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References
section.
Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.
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/security/updates/classification/#important");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2234589");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2241782");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2241796");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2241797");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2259915");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2259918");
# https://access.redhat.com/security/data/csaf/v2/advisories/2024/rhsa-2024_1873.json
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b06ccd78");
script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2024:1873");
script_set_attribute(attribute:"solution", value:
"Update the RHEL shim package based on the guidance in RHSA-2024:1873.");
script_set_cvss_base_vector("CVSS2#AV:A/AC:H/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:C/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-2023-40547");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"exploit_available", value:"false");
script_cwe_id(125, 476, 787);
script_set_attribute(attribute:"vendor_severity", value:"Important");
script_set_attribute(attribute:"vuln_publication_date", value:"2023/12/11");
script_set_attribute(attribute:"patch_publication_date", value:"2024/04/18");
script_set_attribute(attribute:"plugin_publication_date", value:"2024/04/18");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_aus:8.4");
script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_e4s:8.4");
script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_tus:8.4");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim-ia32");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim-x64");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Red Hat 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", "redhat_repos.nasl");
script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/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/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'eq', os_version: os_ver, rhel_version: '8.4')) audit(AUDIT_OS_NOT, 'Red Hat 8.4', 'Red Hat ' + 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 && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);
var constraints = [
{
'repo_relative_urls': [
'content/aus/rhel8/8.4/x86_64/baseos/debug',
'content/aus/rhel8/8.4/x86_64/baseos/os',
'content/aus/rhel8/8.4/x86_64/baseos/source/SRPMS',
'content/e4s/rhel8/8.4/x86_64/baseos/debug',
'content/e4s/rhel8/8.4/x86_64/baseos/os',
'content/e4s/rhel8/8.4/x86_64/baseos/source/SRPMS',
'content/tus/rhel8/8.4/x86_64/baseos/debug',
'content/tus/rhel8/8.4/x86_64/baseos/os',
'content/tus/rhel8/8.4/x86_64/baseos/source/SRPMS'
],
'pkgs': [
{'reference':'shim-ia32-15.8-2.el8_4', 'sp':'4', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'shim-x64-15.8-2.el8_4', 'sp':'4', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE}
]
}
];
var applicable_repo_urls = rhel_determine_applicable_repository_urls(constraints:constraints);
if(applicable_repo_urls == RHEL_REPOS_NO_OVERLAP_MESSAGE) exit(0, RHEL_REPO_NOT_ENABLED);
var flag = 0;
foreach var constraint_array ( constraints ) {
var repo_relative_urls = NULL;
if (!empty_or_null(constraint_array['repo_relative_urls'])) repo_relative_urls = constraint_array['repo_relative_urls'];
foreach var pkg ( constraint_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;
var exists_check = NULL;
var cves = NULL;
if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
if (reference &&
_release &&
rhel_decide_repo_relative_url_check(required_repo_url_list:repo_relative_urls) &&
(applicable_repo_urls || (!exists_check || rpm_exists(release:_release, rpm:exists_check))) &&
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, cves:cves)) flag++;
}
}
if (flag)
{
var subscription_caveat = '\n' +
'NOTE: This vulnerability check contains fixes that apply to\n' +
'packages only available in the Red Hat Enterprise Linux\n' +
'Advanced Update Support, Telco Extended Update Support or Update Services for SAP Solutions repositories.\n' +
'Access to these repositories requires a paid RHEL subscription.\n';
var extra = NULL;
if (isnull(applicable_repo_urls) || !applicable_repo_urls) extra = subscription_caveat + rpm_report_get() + redhat_report_repo_caveat();
else extra = subscription_caveat + rpm_report_get();
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : extra
);
exit(0);
}
else
{
var tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'shim-ia32 / shim-x64');
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-40546
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-40547
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-40548
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-40549
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-40550
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-40551
www.nessus.org/u?b06ccd78
access.redhat.com/errata/RHSA-2024:1873
access.redhat.com/security/updates/classification/#important
bugzilla.redhat.com/show_bug.cgi?id=2234589
bugzilla.redhat.com/show_bug.cgi?id=2241782
bugzilla.redhat.com/show_bug.cgi?id=2241796
bugzilla.redhat.com/show_bug.cgi?id=2241797
bugzilla.redhat.com/show_bug.cgi?id=2259915
bugzilla.redhat.com/show_bug.cgi?id=2259918
CVSS3
Attack Vector
ADJACENT
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
79.6%