Amazon Linux 2 : gfs2-utils (ALAS-2026-4004)

#%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-2026-4004.
##

include('compat.inc');

if (description)
{
  script_id(371787);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/24");

  script_cve_id(
    "CVE-2026-71219",
    "CVE-2026-71220",
    "CVE-2026-71221",
    "CVE-2026-71222"
  );

  script_name(english:"Amazon Linux 2 : gfs2-utils (ALAS-2026-4004)");

  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 gfs2-utils installed on the remote host is prior to 3.1.10-6. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2-2026-4004 advisory.

    A stack overflow vulnerability was found in gfs2-utils. The hash table traversal code in metawalk.c uses
    alloca() with an exponentially-derived size from the untrusted on-disk di_depth field without bounds
    validation. A crafted GFS2 filesystem image with a large di_depth value causes stack exhaustion and a
    denial of service when processed by fsck.gfs2, gfs2_edit, or savemeta. (CVE-2026-71219)

    A stack out-of-bounds write vulnerability was found in gfs2-utils. In gfs2_edit, the di_height field from
    on-disk inode metadata is used as an array index without bounds checking, causing a stack buffer overflow
    that may lead to arbitrary code execution when processing crafted GFS2 filesystem images. (CVE-2026-71220)

    A stack out-of-bounds write vulnerability was found in gfs2-utils. In savemeta, the height value from on-
    disk inode metadata is used as a loop bound without bounds checking, causing a stack buffer overflow that
    may lead to arbitrary code execution when processing crafted GFS2 filesystem images. (CVE-2026-71221)

    A heap out-of-bounds read vulnerability was found in gfs2-utils. The ea_num_ptrs field from on-disk
    extended attribute metadata is consumed without bounds validation, causing a heap buffer over-read that
    may disclose sensitive memory contents or cause a crash when processing crafted GFS2 filesystem images.
    (CVE-2026-71222)

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/ALAS2-2026-4004.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-2026-71219.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-71220.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-71221.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-71222.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update gfs2-utils' or
  or 'yum update --advisory ALAS2-2026-4004' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:L/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:L/AC:H/PR:N/UI:R/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-2026-71220");

  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:"2026/09/03");
  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:gfs2-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gfs2-utils-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_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':'gfs2-utils-3.1.10-6.amzn2.0.1', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'gfs2-utils-debuginfo-3.1.10-6.amzn2.0.1', '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_WARNING,
      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, "gfs2-utils / gfs2-utils-debuginfo");
}