Amazon Linux 2 : vim, --advisory ALAS2-2026-3804 (ALAS-2026-3804)

#%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-2026-3804.
##

include('compat.inc');

if (description)
{
  script_id(328825);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/21");

  script_cve_id("CVE-2026-55693", "CVE-2026-55895", "CVE-2026-57456");

  script_name(english:"Amazon Linux 2 : vim, --advisory ALAS2-2026-3804 (ALAS-2026-3804)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3804 advisory.

    Vim is an open source, command line text editor. Prior to 9.2.0653, the tree_count_words() function in
    src/spellfile.c fills in the word-count fields of a spell-file word trie by walking it iteratively with a
    depth counter. The counter is bounded only by the trie structure itself; it is never checked against the
    size of the fixed MAXWLEN-element stack arrays it indexes (arridx[], curi[], wordcount[]). A crafted
    .spl/.sug file pair, loaded when the user invokes spell suggestion, can drive the descent arbitrarily
    deep, so the function writes past the end of those arrays. This is a stack out-of-bounds write that
    corrupts the call frame and crashes the editor. This vulnerability is fixed in 9.2.0653. (CVE-2026-55693)

    Vim is an open source, command line text editor. Prior to 9.2.0663, a Vimscript code injection
    vulnerability exists in s:NetrwLocalRmFile() in the netrw plugin
    (runtime/pack/dist/opt/netrw/autoload/netrw.vim) when deleting a local file from the browser. A filename
    derived from the buffer's directory listing is interpolated into an Ex command line passed to :execute
    with only the backslash character escaped, allowing a crafted filename containing a bar (|) to terminate
    the intended command and execute arbitrary Vimscript, including shell commands via :call system() and :!.
    This vulnerability is fixed in 9.2.0663. (CVE-2026-55895)

    Vim is an open source, command line text editor. Prior to 9.2.0699, Vim's Python omni-completion
    (runtime/autoload/python3complete.vim and the legacy pythoncomplete.vim) executes reconstructed function
    and class definitions from the current buffer with exec() as part of populating the completion dictionary.
    When reconstructing that source, each scope's docstring is inserted verbatim between triple quotes with no
    escaping, so a hostile buffer can break out of the triple-quoted literal and execute attacker-controlled
    Python during omni-completion. This vulnerability is fixed in 9.2.0699. (CVE-2026-57456)

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/ALAS2-2026-3804.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-2026-55693.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-55895.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-57456.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update vim' or
  or 'yum update --advisory ALAS2-2026-3804' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/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:L/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:"cvss4_vector", value:"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-57456");

  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:"2026/06/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/07/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:vim-X11");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:vim-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:vim-data");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:vim-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:vim-enhanced");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:vim-filesystem");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:vim-minimal");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:xxd");
  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':'vim-common-9.0.2153-1.amzn2.0.8', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-common-9.0.2153-1.amzn2.0.8', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-common-9.0.2153-1.amzn2.0.8', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-data-9.0.2153-1.amzn2.0.8', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-debuginfo-9.0.2153-1.amzn2.0.8', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-debuginfo-9.0.2153-1.amzn2.0.8', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-debuginfo-9.0.2153-1.amzn2.0.8', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-enhanced-9.0.2153-1.amzn2.0.8', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-enhanced-9.0.2153-1.amzn2.0.8', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-enhanced-9.0.2153-1.amzn2.0.8', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-filesystem-9.0.2153-1.amzn2.0.8', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-minimal-9.0.2153-1.amzn2.0.8', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-minimal-9.0.2153-1.amzn2.0.8', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-minimal-9.0.2153-1.amzn2.0.8', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-X11-9.0.2153-1.amzn2.0.8', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-X11-9.0.2153-1.amzn2.0.8', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'vim-X11-9.0.2153-1.amzn2.0.8', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'xxd-9.0.2153-1.amzn2.0.8', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'xxd-9.0.2153-1.amzn2.0.8', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'xxd-9.0.2153-1.amzn2.0.8', '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, "vim-X11 / vim-common / vim-data / etc");
}