AlmaLinux 9.2 [TuxCare] Security Update: lrzsz Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1792053113)

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

include('compat.inc');

if (description)
{
  script_id(366112);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/15");

  script_cve_id("CVE-2026-105840", "CVE-2026-105841", "CVE-2026-105842");
  script_xref(name:"CLSA", value:"2026:1792053113");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: lrzsz Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1792053113)");

  script_set_attribute(attribute:"synopsis", value:
"The AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The AlmaLinux 9.2 host has a package installed that is affected by multiple vulnerabilities as referenced in the TuxCare
ALMALINUX9.2:CLSA-2026:1792053113 advisory.

  - lrzsz before 0.13.0 contains a path traversal vulnerability in the lrz receive utility's restricted mode
    that allows malicious ZMODEM senders to write files outside the current directory using absolute
    pathnames. Because checkpath() in src/lrz.c only rejects '../' sequences unless built with --enable-
    pubdir, attackers can send files named with absolute paths to overwrite any file writable by the receiving
    user. (CVE-2026-105840)

  - lrzsz before 0.13.0 contains an OS command injection vulnerability in the lrz receive utility's pipe mode
    that allows remote senders to execute commands by supplying crafted filenames. When lrz runs under a
    suffixed name such as lrztar, procheader() in src/lrz.c passes the unescaped ZMODEM/YMODEM filename to
    popen(), so shell metacharacters execute as the receiving user. (CVE-2026-105841)

  - lrzsz before 0.13.0 contains a heap-based buffer overflow vulnerability in procheader() of the lrz receive
    utility when copying overlong sender-supplied filenames into Pathname. Malicious ZMODEM senders can supply
    filenames up to 8192 bytes, overflowing the buffer via sprintf() in pipe mode or strcpy() to corrupt heap
    memory and crash lrz. (CVE-2026-105842)

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/almalinux9.2esu/advisories/2026/clsa-2026_1792053113.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?811df31e");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1792053113");
  script_set_attribute(attribute:"solution", value:
"Update the affected lrzsz package based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2026:1792053113.");
  script_set_cvss_base_vector("CVSS2#AV:N/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:N/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:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/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-2026-105841");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-105840");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-105840");

  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:"2026/10/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/15");

  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:"^9.2([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 9.2', '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 ('aarch64' >!< cpu && cpu !~ "^i[3-6]86$" && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '2',
    'pkgs': [
      {'reference':'lrzsz-0.12.20-55.el9.tuxcare.els1', 'sp':'2', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'lrzsz-0.12.20-55.el9.tuxcare.els1', 'sp':'2', 'cpu':'i686', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'lrzsz-0.12.20-55.el9.tuxcare.els1', 'sp':'2', 'cpu':'x86_64', '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, 'lrzsz');
}