Amazon Linux 2 : openssh, --advisory ALAS2-2026-3175 (ALAS-2026-3175)

#%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-2026-3175.
##

include('compat.inc');

if (description)
{
  script_id(299559);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/02/19");

  script_cve_id("CVE-2025-32728", "CVE-2025-61984");
  script_xref(name:"IAVA", value:"2025-A-0258-S");
  script_xref(name:"IAVA", value:"2025-A-0729-S");

  script_name(english:"Amazon Linux 2 : openssh, --advisory ALAS2-2026-3175 (ALAS-2026-3175)");

  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 openssh installed on the remote host is prior to 7.4p1-22. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2-2026-3175 advisory.

    In sshd in OpenSSH before 10.0, the DisableForwarding directive does not adhere to the documentation
    stating that it disables X11 and agent forwarding. (CVE-2025-32728)

    ssh in OpenSSH before 10.1 allows control characters in usernames that originate from certain possibly
    untrusted sources, potentially leading to code execution when a ProxyCommand is used. The untrusted
    sources are the command line and %-sequence expansion of a configuration file. (A configuration file that
    provides a complete literal username is not categorized as an untrusted source.) (CVE-2025-61984)

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/ALAS2-2026-3175.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-2025-32728.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2025-61984.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update openssh' or
  or 'yum update --advisory ALAS2-2026-3175' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:N/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-32728");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/12/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/02/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/02/19");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-askpass");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-cavs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-keycat");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-server-sysvinit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:pam_ssh_agent_auth");
  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("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':'openssh-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-askpass-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-askpass-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-askpass-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-cavs-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-cavs-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-cavs-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-clients-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-clients-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-clients-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-debuginfo-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-debuginfo-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-debuginfo-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-keycat-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-keycat-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-keycat-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-ldap-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-ldap-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-ldap-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-server-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-server-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-server-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-server-sysvinit-7.4p1-22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-server-sysvinit-7.4p1-22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'openssh-server-sysvinit-7.4p1-22.amzn2.0.11', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
    {'reference':'pam_ssh_agent_auth-0.10.3-2.22.amzn2.0.11', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'pam_ssh_agent_auth-0.10.3-2.22.amzn2.0.11', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'pam_ssh_agent_auth-0.10.3-2.22.amzn2.0.11', '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)
{
  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, "openssh / openssh-askpass / openssh-cavs / etc");
}