The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2022-9469 advisory.
A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be considered Low as it’s very complex to an attacker control the encoding and positioning of corrupted Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12. (CVE-2021-3696)
A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform some triage over the heap layout to achieve signifcant results, also the values written into the memory are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2 versions prior grub-2.12. (CVE-2021-3695)
A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12. (CVE-2021-3697)
Integer underflow in grub_net_recv_ip4_packets; A malicious crafted IP packet can lead to an integer underflow in grub_net_recv_ip4_packets() function on rsm->total_len value. Under certain circumstances the total_len value may end up wrapping around to a small integer number which will be used in memory allocation. If the attack succeeds in such way, subsequent operations can write past the end of the buffer. (CVE-2022-28733)
Out-of-bounds write when handling split HTTP headers; When handling split HTTP headers, GRUB2 HTTP code accidentally moves its internal data buffer point by one position. This can lead to a out-of-bound write further when parsing the HTTP request, writing a NULL byte past the buffer. It’s conceivable that an attacker controlled set of packets can lead to corruption of the GRUB2’s internal memory metadata.
(CVE-2022-28734)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2022-9469.
##
include('compat.inc');
if (description)
{
script_id(161928);
script_version("1.9");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/18");
script_cve_id(
"CVE-2021-3695",
"CVE-2021-3696",
"CVE-2021-3697",
"CVE-2022-28733",
"CVE-2022-28734",
"CVE-2022-28735",
"CVE-2022-28736"
);
script_name(english:"Oracle Linux 7 : grub2 (ELSA-2022-9469)");
script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2022-9469 advisory.
- A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may
lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be
considered Low as it's very complex to an attacker control the encoding and positioning of corrupted
Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This
flaw affects grub2 versions prior grub-2.12. (CVE-2021-3696)
- A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may
take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent
secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform
some triage over the heap layout to achieve signifcant results, also the values written into the memory
are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2
versions prior grub-2.12. (CVE-2021-3695)
- A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data
to be written in heap. To a successful to be performed the attacker needs to perform some triage over the
heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data
corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions
prior grub-2.12. (CVE-2021-3697)
- Integer underflow in grub_net_recv_ip4_packets; A malicious crafted IP packet can lead to an integer
underflow in grub_net_recv_ip4_packets() function on rsm->total_len value. Under certain circumstances the
total_len value may end up wrapping around to a small integer number which will be used in memory
allocation. If the attack succeeds in such way, subsequent operations can write past the end of the
buffer. (CVE-2022-28733)
- Out-of-bounds write when handling split HTTP headers; When handling split HTTP headers, GRUB2 HTTP code
accidentally moves its internal data buffer point by one position. This can lead to a out-of-bound write
further when parsing the HTTP request, writing a NULL byte past the buffer. It's conceivable that an
attacker controlled set of packets can lead to corruption of the GRUB2's internal memory metadata.
(CVE-2022-28734)
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://linux.oracle.com/errata/ELSA-2022-9469.html");
script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:M/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:N/AC:H/PR:N/UI:N/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-2021-3696");
script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2022-28733");
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:"2022/06/07");
script_set_attribute(attribute:"patch_publication_date", value:"2022/06/07");
script_set_attribute(attribute:"plugin_publication_date", value:"2022/06/07");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-common");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-ia32");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-ia32-cdboot");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-ia32-modules");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-x64");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-x64-cdboot");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-x64-modules");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-pc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-pc-modules");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-tools");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-tools-extra");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-tools-minimal");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Oracle Linux Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2022-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/local_checks_enabled");
exit(0);
}
include('rpm.inc');
if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
var os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7', 'Oracle Linux ' + os_ver);
if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);
if ('x86_64' >!< cpu) audit(AUDIT_ARCH_NOT, 'x86_64', cpu);
var pkgs = [
{'reference':'grub2-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-common-2.02-0.87.0.21.el7_9.9', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-efi-ia32-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-efi-ia32-cdboot-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-efi-ia32-modules-2.02-0.87.0.21.el7_9.9', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-efi-x64-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-efi-x64-cdboot-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-efi-x64-modules-2.02-0.87.0.21.el7_9.9', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-pc-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-pc-modules-2.02-0.87.0.21.el7_9.9', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-tools-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-tools-extra-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
{'reference':'grub2-tools-minimal-2.02-0.87.0.21.el7_9.9', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
];
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;
var exists_check = NULL;
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (!empty_or_null(package_array['release'])) release = 'EL' + 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 (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
if (reference && release) {
if (exists_check) {
if (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)) flag++;
} else {
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, 'grub2 / grub2-common / grub2-efi-ia32 / etc');
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3695
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3696
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3697
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28733
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28734
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28735
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28736
linux.oracle.com/errata/ELSA-2022-9469.html