Amazon Linux 2 : ant (ALAS-2026-4020)

#%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-2026-4020.
##

include('compat.inc');

if (description)
{
  script_id(371778);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/24");

  script_cve_id("CVE-2026-78254");

  script_name(english:"Amazon Linux 2 : ant (ALAS-2026-4020)");

  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 ant installed on the remote host is prior to 1.9.16-1. It is, therefore, affected by a vulnerability as
referenced in the ALAS2-2026-4020 advisory.

    The ftp and scp tasks of Apache Ant can download files from a remote server. A malicious server can
    provide relative paths that allow it to write outside of the dedicated target directory for the download,
    making it possible to overwrite files of the attacker's choice using the permissions of the user running
    Ant in versions prior to Ant 1.10.18.



    In order to exploit this vulnerability, the server would either have to be malicious or be subject to a
    machine-in-the-middle attack. Additionally in the case of scp or the ftp task using ftps the server must
    pass the server identity checks performed by the tasks.



    For ftp tasks not using ftps a malicious server could act as a machine-in-the-middle to provide malicious
    files.



    Starting with Ant 1.10.18 both tasks will prevent writing outside of the destination directory by default.
    An option is available to disable this behavior in the unlikely case that the  old behavior is required by
    existing build files.



    Mitigations:



    Users of scp and ftp (when using ftps) in any version of Ant should not bypass server identity checks.
    Users of ftp not using ftps should switch to ftps where possible.



    All users are recommended to upgrade to Apache Ant 1.10.18, which fixes this issue. (CVE-2026-78254)

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/ALAS2-2026-4020.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-2026-78254.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update ant' or
  or 'yum update --advisory ALAS2-2026-4020' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/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:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-78254");

  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:"2026/09/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/24");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-antlr");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-apache-bcel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-apache-bsf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-apache-log4j");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-apache-oro");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-apache-regexp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-apache-resolver");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-apache-xalan2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-commons-logging");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-commons-net");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-javadoc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-javamail");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-jdepend");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-jmf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-jsch");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-junit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-manual");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-swing");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ant-testutil");
  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':'ant-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-antlr-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-apache-bcel-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-apache-bsf-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-apache-log4j-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-apache-oro-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-apache-regexp-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-apache-resolver-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-apache-xalan2-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-commons-logging-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-commons-net-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-javadoc-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-javamail-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-jdepend-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-jmf-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-jsch-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-junit-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-manual-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-swing-1.9.16-1.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ant-testutil-1.9.16-1.amzn2.0.2', '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, "ant / ant-antlr / ant-apache-bcel / etc");
}