Amazon Linux 2 : edk2 (ALAS-2024-2539)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2024-2539.
##

include('compat.inc');

if (description)
{
  script_id(197110);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/15");

  script_cve_id("CVE-2024-2511");

  script_name(english:"Amazon Linux 2 : edk2 (ALAS-2024-2539)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"It is, therefore, affected by a vulnerability as referenced in the ALAS2-2024-2539 advisory.

  - Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when
    processing TLSv1.3 sessions Impact summary: An attacker may exploit certain server configurations to
    trigger unbounded memory growth that would lead to a Denial of Service This problem can occur in TLSv1.3
    if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured
    and the default anti-replay protection is in use). In this case, under certain conditions, the session
    cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache
    will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario
    for this failure to force a Denial of Service. It may also happen by accident in normal operation. This
    issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients. The FIPS modules in
    3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue.
    (CVE-2024-2511)

Note that Nessus has not tested for this issue 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/ALAS-2024-2539.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2024-2511.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update edk2' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:N/I:N/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:N/I:N/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-2024-2511");

  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:"2024/04/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/05/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/05/15");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:edk2-aarch64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:edk2-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:edk2-ovmf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:edk2-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:edk2-tools-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:edk2-tools-python");
  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) 2024 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");

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 pkgs = [
    {'reference':'edk2-aarch64-20200801stable-1.amzn2.0.6', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'edk2-debuginfo-20200801stable-1.amzn2.0.6', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'edk2-debuginfo-20200801stable-1.amzn2.0.6', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'edk2-ovmf-20200801stable-1.amzn2.0.6', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'edk2-tools-20200801stable-1.amzn2.0.6', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'edk2-tools-20200801stable-1.amzn2.0.6', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'edk2-tools-doc-20200801stable-1.amzn2.0.6', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'edk2-tools-python-20200801stable-1.amzn2.0.6', '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;
  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_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, "edk2-aarch64 / edk2-debuginfo / edk2-ovmf / etc");
}