Unity Linux 20.1050a / 20.1060a / 20.1070a Security Update: PackageKit (UTSA-2026-149761)

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

include('compat.inc');

if (description)
{
  script_id(374280);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/30");

  script_cve_id("CVE-2026-41651");

  script_name(english:"Unity Linux 20.1050a / 20.1060a / 20.1070a Security Update: PackageKit (UTSA-2026-149761)");

  script_set_attribute(attribute:"synopsis", value:
"The Unity Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the
UTSA-2026-149761 advisory.

    PackageKit is a a D-Bus abstraction layer that allows the user to manage packages in a secure way using a
    cross-distro, cross-architecture API. PackageKit between and including versions 1.0.2 and 1.3.4 is
    vulnerable to a time-of-check time-of-use (TOCTOU) race condition on transaction flags that allows
    unprivileged users to install packages as root and thus leads to a local privilege escalation. This is
    patched in version 1.3.5.

    A local unprivileged user can install arbitrary RPM packages as root, including executing RPM scriptlets,
    without authentication. The vulnerability is a TOCTOU race condition on
    `transaction->cached_transaction_flags`  combined with a silent state-machine guard that discards illegal
    backward transitions while leaving corrupted flags in place. Three bugs exist in `src/pk-transaction.c`:
    1. Unconditional flag overwrite (line 4036): `InstallFiles()` writes caller-supplied flags to
    `transaction->cached_transaction_flags` without checking whether the transaction has already been
    authorized/started. A second call blindly overwrites the flags even while the transaction is RUNNING.
    2. Silent state-transition rejection (lines 873882): `pk_transaction_set_state()` silently discards
    backward state transitions (e.g. `RUNNING`  `WAITING_FOR_AUTH`) but the flag overwrite at step 1
    already happened. The transaction continues running with corrupted flags.
    3. Late flag read at execution time (lines 22732277): The scheduler's idle callback reads
    cached_transaction_flags at dispatch time, not at authorization time. If flags were overwritten between
    authorization and execution, the backend sees the attacker's flags.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://src.uniontech.com/#/security_advisory_detail?utsa_id=UTSA-2026-149761
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?fa1bbcd9");
  script_set_attribute(attribute:"see_also", value:"http://www.openwall.com/lists/oss-security/2026/04/22/6");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:11504");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:11635");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:17558");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:17560");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:17561");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:18024");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:18031");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:18036");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:19141");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:19354");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:19454");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:19601");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:22146");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/CVE-2026-41651");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2460604");
  # https://github.com/PackageKit/PackageKit/blob/04057883189efa225a7c785591aa87cb299782f8/src/pk-transaction.c#L2273-L2277
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?53d574f4");
  # https://github.com/PackageKit/PackageKit/blob/04057883189efa225a7c785591aa87cb299782f8/src/pk-transaction.c#L4036
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?c5dfd8fc");
  # https://github.com/PackageKit/PackageKit/blob/04057883189efa225a7c785591aa87cb299782f8/src/pk-transaction.c#L873-L882
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a82fb53e");
  # https://github.com/PackageKit/PackageKit/security/advisories/GHSA-f55j-vvr9-69xv
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?17deb91b");
  # https://github.security.telekom.com/2026/04/pack2theroot-linux-local-privilege-escalation.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b9554ac9");
  # https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41651.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?23c43aff");
  script_set_attribute(attribute:"solution", value:
"Update the affected PackageKit package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-41651");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/04/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/30");

  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:"Unity 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/UOS-Server/release", "Host/UOS-Server/rpm-list", "Host/cpu");

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

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) || 'UOS Server' >!< os_product) audit(AUDIT_OS_NOT, 'UOS Server');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'UOS Server');
if (! preg(pattern:"^(20.1050a|20.1060a|20.1070a)([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1050a / 20.1060a / 20.1070a', 'UOS Server ' + os_version);

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

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('aarch64' >!< cpu && 'amd64' >!< cpu && 'loongarch64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1050a',
    'pkgs': [
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1050a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1050a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1050a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1050a', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '20',
    'sp': '1060a',
    'pkgs': [
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1060a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1060a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1060a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1060a', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1070a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'PackageKit-1.1.10-2.uelc20.02', 'sp':'1070a', '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_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, 'PackageKit');
}