Amazon Linux 2 : rsyslog (ALAS-2026-3967)

#%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-2026-3967.
##

include('compat.inc');

if (description)
{
  script_id(365273);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/12");

  script_cve_id("CVE-2026-92709");

  script_name(english:"Amazon Linux 2 : rsyslog (ALAS-2026-3967)");

  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 rsyslog installed on the remote host is prior to 8.24.0-57. It is, therefore, affected by a vulnerability
as referenced in the ALAS2-2026-3967 advisory.

    rsyslog's omfile dynaFile facility intentionally allows templates to generate flexible output paths. This
    supports valid deployments that route logs into different directories or use dynamically generated file
    names.

    A deployment becomes unsafe when a dynaFile template uses a value influenced by untrusted input as a path
    component without explicit secure-path handling. In that configuration, the rendered path can escape the
    operator's intended log directory.

    This is not limited to the RFC5424 HOSTNAME field. Any untrusted value that reaches a dynaFile path
    component can create the condition.

    An attacker who can influence such a value may cause rsyslog to create or append to files outside the
    intended output directory, subject to rsyslog's effective privileges and host confinement.

    The practical result depends on the deployment. Mandatory access controls, systemd sandboxing, filesystem
    permissions, the configured input modules, and the selected output template can all limit or prevent
    impact. A code-execution outcome requires additional, deployment-specific conditions and is not
    representative of default distribution configurations.

    Default Debian and Ubuntu configurations do not enable a network input and a dynaFile action of this form.
    The affected configuration must be explicitly deployed. (CVE-2026-92709)

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//AL2/ALAS2-2026-3967.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-2026-92709.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update rsyslog' or
  or 'yum update --advisory ALAS2-2026-3967' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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-2026-92709");

  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:"2026/10/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-crypto");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-elasticsearch");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-gnutls");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-gssapi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-kafka");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-libdbi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-mmaudit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-mmjsonparse");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-mmkubernetes");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-mmnormalize");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-mmsnmptrapd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-mysql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-pgsql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-relp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-snmp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rsyslog-udpspoof");
  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) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.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 pkgs = [
    {'reference':'rsyslog-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-crypto-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-crypto-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-crypto-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-debuginfo-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-debuginfo-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-debuginfo-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-doc-8.24.0-57.amzn2.2.0.4', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-elasticsearch-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-elasticsearch-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-elasticsearch-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-gnutls-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-gnutls-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-gnutls-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-gssapi-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-gssapi-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-gssapi-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-kafka-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-kafka-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-kafka-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-libdbi-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-libdbi-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-libdbi-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmaudit-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmaudit-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmaudit-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmjsonparse-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmjsonparse-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmjsonparse-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmkubernetes-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmkubernetes-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmkubernetes-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmnormalize-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmnormalize-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmnormalize-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmsnmptrapd-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmsnmptrapd-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mmsnmptrapd-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mysql-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mysql-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-mysql-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-pgsql-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-pgsql-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-pgsql-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-relp-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-relp-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-relp-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-snmp-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-snmp-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-snmp-8.24.0-57.amzn2.2.0.4', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-udpspoof-8.24.0-57.amzn2.2.0.4', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-udpspoof-8.24.0-57.amzn2.2.0.4', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'rsyslog-udpspoof-8.24.0-57.amzn2.2.0.4', '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_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, "rsyslog / rsyslog-crypto / rsyslog-debuginfo / etc");
}