AlmaLinux 9.6 [TuxCare] Security Update: rsync / rsync-daemon / rsync-rrsync Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1788520884)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(360328);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id("CVE-2026-53789", "CVE-2026-70457", "CVE-2026-70461");
  script_xref(name:"CLSA", value:"2026:1788520884");

  script_name(english:"AlmaLinux 9.6 [TuxCare] Security Update: rsync / rsync-daemon / rsync-rrsync Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1788520884)");

  script_set_attribute(attribute:"synopsis", value:
"The AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The AlmaLinux 9.6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare
ALMALINUX9.6:CLSA-2026:1788520884 advisory.

  - rsync before 3.5.0 contains an improper path handling vulnerability that allows a malicious sender to
    expand the scope of --delete operations beyond the intended destination subtree by sending a crafted file
    list that causes rsync to reclassify implied parent directory entries or treat synthetic paths as the
    transfer root. Attackers can exploit multiple variants including implied parent reclassification,
    synthetic root path construction, legacy protocol behavior below version 30, and non-directory root
    handling to cause the receiver to delete files outside the authorized destination directory.
    (CVE-2026-53789)

  - rsync 3.2.3 before 3.5.0 contains an out-of-bounds write in parse_size_arg() where the return value of
    snprintf() is used directly as an index into a .bss-segment array without bounds checking. When snprintf
    truncates the formatted size string, the return value equals the number of characters that would have been
    written including the truncated portion, and this value may exceed the array length. The subsequent
    indexed write targets memory outside the intended array bounds, corrupting .bss memory. (CVE-2026-70457)

  - rsync 3.2.5 before 3.5.0 contains a heap out-of-bounds write vulnerability that allows remote
    unauthenticated attackers to write one attacker-controlled byte past the end of a heap allocation by
    supplying a crafted files-from entry. Attackers can trigger the vulnerability against a read-only rsync
    daemon module by providing a files-from entry containing both an interior and trailing backslash, causing
    the add_implied_include() function to under-count the trailing backslash when sizing the destination
    buffer. (CVE-2026-70461)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/tuxcare9.6esu/advisories/2026/clsa-2026_1788520884.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?412e8e27");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1788520884");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1788520884.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/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:L/PR:N/UI:N/S:U/C:N/I:L/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:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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-2026-53789");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-70457");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-70461");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_severity", value:"Critical");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/01");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Alma 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/OS/extended-third-party", "Host/local_checks_enabled", "Host/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  exit(0);
}
include('rpm2.inc');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (empty_or_null(third_party_support) || third_party_support != 'TuxCare') exit(0, 'TuxCare support not enabled.');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'AlmaLinux' >!< os_product) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
if (! preg(pattern:"^9.6([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 9.6', 'AlmaLinux ' + os_version);

if (!get_kb_item('Host/AlmaLinux/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '6',
    'pkgs': [
      {'reference':'rsync-3.2.5-3.el9_6.tuxcare.els11', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rsync-daemon-3.2.5-3.el9_6.tuxcare.els11', 'sp':'6', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rsync-rrsync-3.2.5-3.el9_6.tuxcare.els11', 'sp':'6', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(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, 'rsync / rsync-daemon / rsync-rrsync');
}