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HistorySep 06, 2022 - 12:00 a.m.

Amazon Linux 2022 : (ALAS2022-2022-039)

2022-09-0600:00:00

www.tenable.com

amazon linux 2022

cpu vulnerabilities

data leakage

information disclosure

privilege escalation

cache speculation

spectre-bhb

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

CVSS4

8.6

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/SC:H/VI:H/SI:H/VA:N/SA:N

EPSS

0.975

Percentile

100.0%

JSON

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2022-2022-039 advisory.

Some AMD CPUs may transiently execute beyond unconditional direct branches, which may potentially result in data leakage. (CVE-2021-26341)
LFENCE/JMP (mitigation V2-2) may not sufficiently mitigate CVE-2017-5715 on some AMD CPUs.
(CVE-2021-26401)
Non-transparent sharing of branch predictor selectors between contexts in some Intel® Processors may allow an authorized user to potentially enable information disclosure via local access. (CVE-2022-0001)
Non-transparent sharing of branch predictor within a context in some Intel® Processors may allow an authorized user to potentially enable information disclosure via local access. (CVE-2022-0002)
A flaw was found in the way the flags member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe and push_pipe functions in the Linux kernel and could thus contain stale values. An unprivileged local user could use this flaw to write to pages in the page cache backed by read only files and as such escalate their privileges on the system. (CVE-2022-0847)
A use-after-free exists in the Linux Kernel in tc_new_tfilter that could allow a local attacker to gain privilege escalation. The exploit requires unprivileged user namespaces. We recommend upgrading past commit 04c2a47ffb13c29778e2a14e414ad4cb5a5db4b5 (CVE-2022-1055)
Certain Arm Cortex and Neoverse processors through 2022-03-08 do not properly restrict cache speculation, aka Spectre-BHB. An attacker can leverage the shared branch history in the Branch History Buffer (BHB) to influence mispredicted branches. Then, cache allocation can allow the attacker to obtain sensitive information. (CVE-2022-23960)

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 2022 Security Advisory ALAS2022-2022-039.
##

include('compat.inc');

if (description)
{
  script_id(164727);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/01/13");

  script_cve_id(
    "CVE-2021-26341",
    "CVE-2021-26401",
    "CVE-2022-0001",
    "CVE-2022-0002",
    "CVE-2022-0847",
    "CVE-2022-1055",
    "CVE-2022-23960"
  );
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/05/16");

  script_name(english:"Amazon Linux 2022 :  (ALAS2022-2022-039)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2022 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2022-2022-039 advisory.

  - Some AMD CPUs may transiently execute beyond unconditional direct branches, which may potentially result
    in data leakage. (CVE-2021-26341)

  - LFENCE/JMP (mitigation V2-2) may not sufficiently mitigate CVE-2017-5715 on some AMD CPUs.
    (CVE-2021-26401)

  - Non-transparent sharing of branch predictor selectors between contexts in some Intel(R) Processors may
    allow an authorized user to potentially enable information disclosure via local access. (CVE-2022-0001)

  - Non-transparent sharing of branch predictor within a context in some Intel(R) Processors may allow an
    authorized user to potentially enable information disclosure via local access. (CVE-2022-0002)

  - A flaw was found in the way the flags member of the new pipe buffer structure was lacking proper
    initialization in copy_page_to_iter_pipe and push_pipe functions in the Linux kernel and could thus
    contain stale values. An unprivileged local user could use this flaw to write to pages in the page cache
    backed by read only files and as such escalate their privileges on the system. (CVE-2022-0847)

  - A use-after-free exists in the Linux Kernel in tc_new_tfilter that could allow a local attacker to gain
    privilege escalation. The exploit requires unprivileged user namespaces. We recommend upgrading past
    commit 04c2a47ffb13c29778e2a14e414ad4cb5a5db4b5 (CVE-2022-1055)

  - Certain Arm Cortex and Neoverse processors through 2022-03-08 do not properly restrict cache speculation,
    aka Spectre-BHB. An attacker can leverage the shared branch history in the Branch History Buffer (BHB) to
    influence mispredicted branches. Then, cache allocation can allow the attacker to obtain sensitive
    information. (CVE-2022-23960)

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/AL2022/ALAS-2022-039.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-26341.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-26401.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-0001.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-0002.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-0847.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-1055.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-23960.html");
  script_set_attribute(attribute:"solution", value:
"Run 'dnf update --releasever=2022.0.20220308 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-2022-0847");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2022-1055");

  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:'Dirty Pipe Local Privilege Escalation via CVE-2022-0847');
  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:"2022/03/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/03/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/09/06");

  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-livepatch-5.15.25-14.106");
  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:python3-perf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python3-perf-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2022");
  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");
  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 release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
var os_ver = os_ver[1];
if (os_ver != "-2022")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2022", "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-2021-26341", "CVE-2021-26401", "CVE-2022-0001", "CVE-2022-0002", "CVE-2022-0847", "CVE-2022-1055", "CVE-2022-23960");
  if (hotfix_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "kpatch hotfix for ALAS2022-2022-039");
  }
  else
  {
    __rpm_report = hotfix_reporting_text();
  }
}
var pkgs = [
    {'reference':'bpftool-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'bpftool-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'bpftool-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'bpftool-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-common-aarch64-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-common-x86_64-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-5.15.25-14.106.amzn2022', 'cpu':'i686', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-livepatch-5.15.25-14.106-1.0-0.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-livepatch-5.15.25-14.106-1.0-0.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-devel-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-devel-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'aarch64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-debuginfo-5.15.25-14.106.amzn2022', 'cpu':'x86_64', 'release':'AL-2022', 'rpm_spec_vers_cmp':TRUE}
];

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");
}