Amazon Linux 2 : perl-DBI, --advisory ALAS2-2026-3871 (ALAS-2026-3871)

#%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-2026-3871.
##

include('compat.inc');

if (description)
{
  script_id(341884);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/31");

  script_cve_id("CVE-2026-73194");

  script_name(english:"Amazon Linux 2 : perl-DBI, --advisory ALAS2-2026-3871 (ALAS-2026-3871)");

  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 perl-DBI installed on the remote host is prior to 1.627-4. It is, therefore, affected by a vulnerability
as referenced in the ALAS2-2026-3871 advisory.

    DBI versions before 1.652 for Perl allow a heap out-of-bounds write via an unvalidated numeric placeholder
    that sets the binder counter in preparse.

    preparse reserves seven output bytes per input byte, the width of the longest ':p99999' expansion. The
    ':N' branch parses the number with `atoi(src)` and assigns it to the binder counter with no range check,
    so a statement containing ':2147483648' leaves the counter negative (-2147483648 with glibc, where atoi
    wraps). Each following '?' then expands through `sprintf(start, :p%d, idx++)` to ':p-2147483648', 14
    bytes with the terminating NUL where the buffer budgets 7. The placeholder limit added in 1.650 tests the
    counter against 99,999, which a negative counter passes.

    Any caller that preparses an untrusted statement into ':pN' style placeholders gets a heap out-of-bounds
    write that grows with the number of '?' marks following the poisoned placeholder. The '?' and '%s' return
    styles compare the parsed number against the expected sequence and error out, and are unaffected.
    (CVE-2026-73194)

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/ALAS2-2026-3871.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-2026-73194.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update perl-DBI' or
  or 'yum update --advisory ALAS2-2026-3871' 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: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-2026-73194");

  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:"2026/08/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/31");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perl-DBI");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perl-DBI-debuginfo");
  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_info.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':'perl-DBI-1.627-4.amzn2.0.7', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perl-DBI-1.627-4.amzn2.0.7', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perl-DBI-1.627-4.amzn2.0.7', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perl-DBI-debuginfo-1.627-4.amzn2.0.7', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perl-DBI-debuginfo-1.627-4.amzn2.0.7', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perl-DBI-debuginfo-1.627-4.amzn2.0.7', '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, "perl-DBI / perl-DBI-debuginfo");
}