AlmaLinux 9.6 [TuxCare] Security Update: rsync / rsync-daemon / rsync-rrsync Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1789783256)

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

include('compat.inc');

if (description)
{
  script_id(353044);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id(
    "CVE-2026-53785",
    "CVE-2026-53790",
    "CVE-2026-53794",
    "CVE-2026-70453",
    "CVE-2026-70456",
    "CVE-2026-70458",
    "CVE-2026-70462"
  );
  script_xref(name:"CLSA", value:"2026:1789783256");

  script_name(english:"AlmaLinux 9.6 [TuxCare] Security Update: rsync / rsync-daemon / rsync-rrsync Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1789783256)");

  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-2026:1789783256 advisory.

  - rsync before 3.5.0 contains a path traversal vulnerability that allows a malicious sender to write files
    outside the intended destination directory tree by crafting relative paths with symlink components in
    --relative mode. The make_path() function follows symlinks pointing outside the destination tree while
    creating intermediate directories without verifying that created paths remain within the destination
    boundary, enabling arbitrary file writes on the receiver's filesystem. (CVE-2026-53785)

  - rsync before 3.5.0 contains multiple command and argument injection vulnerabilities that allow attackers
    to execute arbitrary commands by supplying malicious input through several code paths, including the
    RSYNC_CONNECT_PROG environment variable, daemon hooks, the rsync-ssl wrapper, and remote-shell command
    newline injection. Attackers can inject shell metacharacters or newline characters into unsanitized user-
    supplied values such as hostnames and hostspecs to execute arbitrary commands under the privileges of the
    rsync process or the invoking user. (CVE-2026-53790)

  - rsync before 3.5.0 contains a logic error in --max-alloc handling that allows a sender or configuration
    setting --max-alloc=0 to disable allocation sanity checks entirely rather than enforcing a zero-byte cap.
    Attackers can exploit this flaw to cause the receiver to attempt unbounded memory allocations for file
    list and data structures, potentially exhausting available memory and causing a denial of service.
    (CVE-2026-53794)

  - rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that
    allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A
    sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU
    resources with a modest number of crafted entries, causing a sustained denial of service. (CVE-2026-70453)

  - rsync 3.0.1 before 3.5.0 contains an out-of-bounds write vulnerability in the read_args() function that
    allows a malicious sender to corrupt adjacent heap memory by sending a crafted argument list. When the
    argument count causes the argv allocation to be exactly full, the trailing NULL terminator is written one
    slot beyond the allocation boundary, corrupting adjacent heap memory. (CVE-2026-70456)

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_1789783256.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?21890ab4");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1789783256");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1789783256.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/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:H/AT:N/PR:N/UI:N/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-2026-70458");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-53790");

  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:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/30");

  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.els18', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rsync-daemon-3.2.5-3.el9_6.tuxcare.els18', 'sp':'6', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rsync-rrsync-3.2.5-3.el9_6.tuxcare.els18', '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');
}