The version of kernel installed on the remote host is prior to 5.4.209-116.363. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.4-2022-034 advisory.
When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel will write memory out of bounds. (CVE-2021-33655)
An issue was discovered in the Linux kernel through 5.18.9. A type confusion bug in nft_set_elem_init (leading to a buffer overflow) could be used by a local attacker to escalate privileges, a different vulnerability than CVE-2022-32250. (The attacker can obtain root access, but must start with an unprivileged user namespace to obtain CAP_NET_ADMIN access.) This can be fixed in nft_setelem_parse_data in net/netfilter/nf_tables_api.c. (CVE-2022-34918)
An issue was discovered in the Linux kernel through 5.18.14. xfrm_expand_policies in net/xfrm/xfrm_policy.c can cause a refcount to be dropped twice. (CVE-2022-36879)
nfqnl_mangle in net/netfilter/nfnetlink_queue.c in the Linux kernel through 5.18.14 allows remote attackers to cause a denial of service (panic) because, in the case of an nf_queue verdict with a one-byte nfta_payload attribute, an skb_pull can encounter a negative skb->len. (CVE-2022-36946)
An out-of-bounds write flaw was found in the Linux kernel’s framebuffer-based console driver functionality in the way a user triggers ioctl FBIOPUT_VSCREENINFO with malicious data. This flaw allows a local user to crash or potentially escalate their privileges on the system. (CVE-2021-33655) (CVE-2022-21505)
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 Amazon Linux 2 Security Advisory ALASKERNEL-5.4-2022-034.
##
include('compat.inc');
if (description)
{
script_id(164357);
script_version("1.6");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/05/02");
script_cve_id(
"CVE-2021-33655",
"CVE-2022-21505",
"CVE-2022-34918",
"CVE-2022-36879",
"CVE-2022-36946",
"CVE-2023-2177"
);
script_name(english:"Amazon Linux 2 : kernel (ALASKERNEL-5.4-2022-034)");
script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
script_set_attribute(attribute:"description", value:
"The version of kernel installed on the remote host is prior to 5.4.209-116.363. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2KERNEL-5.4-2022-034 advisory.
- When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel will write memory out of
bounds. (CVE-2021-33655)
- An issue was discovered in the Linux kernel through 5.18.9. A type confusion bug in nft_set_elem_init
(leading to a buffer overflow) could be used by a local attacker to escalate privileges, a different
vulnerability than CVE-2022-32250. (The attacker can obtain root access, but must start with an
unprivileged user namespace to obtain CAP_NET_ADMIN access.) This can be fixed in nft_setelem_parse_data
in net/netfilter/nf_tables_api.c. (CVE-2022-34918)
- An issue was discovered in the Linux kernel through 5.18.14. xfrm_expand_policies in
net/xfrm/xfrm_policy.c can cause a refcount to be dropped twice. (CVE-2022-36879)
- nfqnl_mangle in net/netfilter/nfnetlink_queue.c in the Linux kernel through 5.18.14 allows remote
attackers to cause a denial of service (panic) because, in the case of an nf_queue verdict with a one-byte
nfta_payload attribute, an skb_pull can encounter a negative skb->len. (CVE-2022-36946)
- An out-of-bounds write flaw was found in the Linux kernel's framebuffer-based console driver
functionality in the way a user triggers ioctl FBIOPUT_VSCREENINFO with malicious data. This flaw allows a
local user to crash or potentially escalate their privileges on the system. (CVE-2021-33655)
(CVE-2022-21505)
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://alas.aws.amazon.com/AL2/ALASKERNEL-5.4-2022-034.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-33655.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-21505.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-34918.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-36879.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-36946.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-2177.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
script_set_attribute(attribute:"solution", value:
"Run 'yum update kernel' to update your system.");
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-2022-34918");
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:'Netfilter nft_set_elem_init Heap Overflow Privilege Escalation');
script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2022/07/04");
script_set_attribute(attribute:"patch_publication_date", value:"2022/08/15");
script_set_attribute(attribute:"plugin_publication_date", value:"2022/08/23");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:bpftool");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:bpftool-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-headers");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python-perf");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python-perf-debuginfo");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Amazon Linux Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl", "kpatch.nasl");
script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");
exit(0);
}
include("rpm.inc");
include("hotfixes.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
if (get_one_kb_item("Host/kpatch/kernel-cves"))
{
set_hotfix_type("kpatch");
var cve_list = make_list("CVE-2021-33655", "CVE-2022-21505", "CVE-2022-34918", "CVE-2022-36879", "CVE-2022-36946", "CVE-2023-2177");
if (hotfix_cves_check(cve_list))
{
audit(AUDIT_PATCH_INSTALLED, "kpatch hotfix for ALASKERNEL-5.4-2022-034");
}
else
{
__rpm_report = hotfix_reporting_text();
}
}
var pkgs = [
{'reference':'bpftool-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'bpftool-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'bpftool-debuginfo-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'bpftool-debuginfo-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-common-aarch64-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-common-x86_64-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-devel-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-devel-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-headers-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-headers-5.4.209-116.363.amzn2', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-headers-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-debuginfo-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-debuginfo-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-devel-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-devel-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-debuginfo-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-debuginfo-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-debuginfo-5.4.209-116.363.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-debuginfo-5.4.209-116.363.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'}
];
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 = 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 && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
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
{
var tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "bpftool / bpftool-debuginfo / kernel / etc");
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-33655
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-21505
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-34918
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-36879
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-36946
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-2177
alas.aws.amazon.com/AL2/ALASKERNEL-5.4-2022-034.html
alas.aws.amazon.com/cve/html/CVE-2021-33655.html
alas.aws.amazon.com/cve/html/CVE-2022-21505.html
alas.aws.amazon.com/cve/html/CVE-2022-34918.html
alas.aws.amazon.com/cve/html/CVE-2022-36879.html
alas.aws.amazon.com/cve/html/CVE-2022-36946.html
alas.aws.amazon.com/cve/html/CVE-2023-2177.html
alas.aws.amazon.com/faqs.html