Amazon Linux 2023 : gnupg2, gnupg2-minimal, gnupg2-smime (ALAS2023-2025-1107)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2023 Security Advisory ALAS2023-2025-1107.
##

include('compat.inc');

if (description)
{
  script_id(243460);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/01/30");

  script_cve_id("CVE-2025-30258");
  script_xref(name:"IAVA", value:"2026-A-0085");

  script_name(english:"Amazon Linux 2023 : gnupg2, gnupg2-minimal, gnupg2-smime (ALAS2023-2025-1107)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2023 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2025-1107 advisory.

    In GnuPG before 2.5.5, if a user chooses to import a certificate with certain crafted subkey data that
    lacks a valid backsig or that has incorrect usage flags, the user loses the ability to verify signatures
    made from certain other signing keys, aka a verification DoS.

    Exploitation of this vulnerability requires the customer to manually import a crafted certificate
    containing fingerprints that will then be used to verify signatures. Considering the tradeoff between the
    stability of Amazon Linux and the exploitation complexity of CVE-2025-30258, a fix will not be provided
    for gnupg2 in Amazon Linux 2 at this time. Users are advised to mitigate this issue by not importing
    suspicious GPG certificates and deleting any malicious keys from their keyrings. (CVE-2025-30258)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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//AL2023/ALAS2023-2025-1107.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-2025-30258.html");
  script_set_attribute(attribute:"solution", value:
"Run 'dnf update gnupg2 --releasever 2023.8.20250721' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:N/I:N/A:P");
  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:N/UI:R/S:C/C:N/I:N/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-30258");

  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:"2025/03/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/08/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/08/04");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-minimal");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-minimal-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-smime");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-smime-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2023");
  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) 2025-2026 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("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 != "-2023")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2023", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var pkgs = [
    {'reference':'gnupg2-2.3.7-1.amzn2023.0.5', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-2.3.7-1.amzn2023.0.5', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-debuginfo-2.3.7-1.amzn2023.0.5', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-debuginfo-2.3.7-1.amzn2023.0.5', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-debugsource-2.3.7-1.amzn2023.0.5', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-debugsource-2.3.7-1.amzn2023.0.5', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-minimal-2.3.7-1.amzn2023.0.5', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-minimal-2.3.7-1.amzn2023.0.5', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-minimal-debuginfo-2.3.7-1.amzn2023.0.5', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-minimal-debuginfo-2.3.7-1.amzn2023.0.5', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-smime-2.3.7-1.amzn2023.0.5', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-smime-2.3.7-1.amzn2023.0.5', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-smime-debuginfo-2.3.7-1.amzn2023.0.5', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gnupg2-smime-debuginfo-2.3.7-1.amzn2023.0.5', 'cpu':'x86_64', 'release':'AL-2023', '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)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_NOTE,
      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, "gnupg2 / gnupg2-debuginfo / gnupg2-debugsource / etc");
}