Amazon Linux 2 : docker, --advisory ALAS2ECS-2026-131 (ALASECS-2026-131)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALASECS-2026-131.
##

include('compat.inc');

if (description)
{
  script_id(325565);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/08");

  script_cve_id(
    "CVE-2026-27145",
    "CVE-2026-41567",
    "CVE-2026-42504",
    "CVE-2026-42507"
  );
  script_xref(name:"IAVB", value:"2026-B-0146");

  script_name(english:"Amazon Linux 2 : docker, --advisory ALAS2ECS-2026-131 (ALASECS-2026-131)");

  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 docker installed on the remote host is prior to 25.0.16-1. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2ECS-2026-131 advisory.

    (*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject
    Alternative Name (SAN) entries. This caused strings.Split(host, .) to execute repeatedly on the same
    input hostname. With a large DNS SAN list, verification costs scaled quadratically based on the number of
    SAN entries multiplied by the hostname's label count. Because x509.Verify validates hostnames before
    building the certificate chain, this overhead occurred even for untrusted certificates. (CVE-2026-27145)

    Moby is an open source container framework. In versions prior to 29.5.1 and in moby/moby v2 prior to
    v2.0.0-beta.14, when a compressed archive is uploaded to a container via `PUT /containers/{id}/archive` or
    piped through `docker cp -`, the daemon resolves decompression binaries (such as `xz` or `unpigz`) from
    the container's filesystem rather than the host's due to incorrect ordering of operations. A malicious
    container image containing a trojanized decompression binary can achieve arbitrary code execution with
    full daemon privileges, including host root UID and unrestricted capabilities, when a user uploads a
    compressed (xz or gzip) archive into that container. This issue is fixed in Docker Engine 29.5.1 and
    moby/moby v2.0.0-beta.14. Workarounds include only running containers from trusted images, using
    authorization plugins to restrict access to the `PUT /containers/{id}/archive` endpoint, and avoiding
    piping compressed archives into containers created from untrusted images (CVE-2026-41567)

    Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive
    CPU. (CVE-2026-42504)

    When returning errors, functions in the net/textproto package would include its input as part of the
    error. This might allow an attacker to inject misleading content to errors that are printed or logged.
    (CVE-2026-42507)

Tenable has extracted the preceding description block directly from the tested product 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://alas.aws.amazon.com//AL2/ALAS2ECS-2026-131.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-27145.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-41567.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-42504.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-42507.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update docker' or
  or 'yum update --advisory ALAS2ECS-2026-131' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:N/I:P/A:C");
  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:L/UI:R/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-2026-27145");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-41567");

  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:"2026/05/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/07/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/08");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:docker");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:docker-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2026 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("rpm2.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);

var REPOS_FOUND = TRUE;
var extras_list = get_kb_item("Host/AmazonLinux/extras_label_list");
if (isnull(extras_list)) REPOS_FOUND = FALSE;
var repository = '"amzn2extra-ecs"';
if (REPOS_FOUND && (repository >!< extras_list)) exit(0, AFFECTED_REPO_NOT_ENABLED);

var pkgs = [
    {'reference':'docker-25.0.16-1.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'docker-25.0.16-1.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'docker-debuginfo-25.0.16-1.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'docker-debuginfo-25.0.16-1.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', '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;
  var cves = 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 (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  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, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = rpm_report_get();
  if (!REPOS_FOUND) extra = rpm_report_get() + report_repo_caveat();
  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, "docker / docker-debuginfo");
}