Fedora 45 : btrfs-backup-ng (2026-a44f471fef)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2026-a44f471fef
#

include('compat.inc');

if (description)
{
  script_id(374716);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/11/01");
  script_xref(name:"FEDORA", value:"2026-a44f471fef");

  script_name(english:"Fedora 45 : btrfs-backup-ng (2026-a44f471fef)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Fedora 45 host has a package installed that is affected by a vulnerability as referenced in the
FEDORA-2026-a44f471fef advisory.

    Update to 0.9.20. This replaces the 0.9.19 update before it reached
    testing. It carries the 0.9.17 security fix (GHSA-5xvm-66c9-p5ph), the
    0.9.18 fix for 0.9.17's btrfs lock regression, three concurrency and
    accounting fixes from 0.9.19, and 0.9.20's fix for the shared-lock
    retry bound, which the previous Fedora build carried as a patch.
    0.9.17 through 0.9.19 were not shipped to this release.

    Security: the lock store created directories, wrote holder records and
    read them back with operations that followed a symbolic link. If the
    lock-store directory on a backup location was writable by another
    local account, a planted symlink could redirect those writes and
    reads; with a backup run as root, as a scheduled backup usually is,
    that let a less privileged local user steer a root write or read.
    Locally the lock store now works on O_NOFOLLOW file descriptors, and
    over ssh each directory component is created with a plain mkdir,
    records are written under set -C, and a record that is a link or not
    a regular file is refused.

    Breaking: a lock-store directory writable by its group or by everyone
    is now refused with an error naming the directory and the remedy
    (chmod go-w <path>). A store created by an earlier version under an
    interactive umask 002 is mode 0775 and will be refused until tightened;
    stores created by a root timer or over ssh are 0755 and unaffected.
    New stores are created 0755 regardless of umask.

    Also fixed since 0.9.16:
    - A pruned raw stream whose .meta sidecar could not be removed was
    counted as both deleted and failed; the sidecar is now a warning.
    - A shared snapshot pin no longer fails with could not lock ...
    refusing to continue when another holder releases at the same
    instant, including under heavy contention on a slow machine.
    - A released shared pin can no longer be revived by an orphaned
    keep-alive, and the sweep of abandoned holder records re-checks a
    record's age at the moment it removes it.

    No configuration or on-disk format changes. This update includes all
    changes since 0.9.16.

    Advisory:
    https://github.com/berrym/btrfs-backup-ng/security/advisories/GHSA-5xvm-66c9-p5ph
    Full changelog:
    https://github.com/berrym/btrfs-backup-ng/blob/v0.9.20/CHANGELOG.md

    ----

    Update to 0.9.19. This replaces the 0.9.18 update before it reached
    testing, so it carries the 0.9.17 security fix (GHSA-5xvm-66c9-p5ph),
    the 0.9.18 fix for 0.9.17's btrfs lock regression, and three
    concurrency and accounting fixes from 0.9.19. 0.9.17 and 0.9.18 were
    not shipped to this release.

    Security: the lock store created directories, wrote holder records and
    read them back with operations that followed a symbolic link. If the
    lock-store directory on a backup location was writable by another
    local account, a planted symlink could redirect those writes and
    reads; with a backup run as root, as a scheduled backup usually is,
    that let a less privileged local user steer a root write or read.
    Locally the lock store now works on O_NOFOLLOW file descriptors, and
    over ssh each directory component is created with a plain mkdir,
    records are written under set -C, and a record that is a link or not
    a regular file is refused.

    Breaking: a lock-store directory writable by its group or by everyone
    is now refused with an error naming the directory and the remedy
    (chmod go-w <path>). A store created by an earlier version under an
    interactive umask 002 is mode 0775 and will be refused until tightened;
    stores created by a root timer or over ssh are 0755 and unaffected.
    New stores are created 0755 regardless of umask.

    Also fixed since 0.9.16:
    - A pruned raw stream whose .meta sidecar could not be removed was
    counted as both deleted and failed; the sidecar is now a warning.
    - A shared snapshot pin no longer fails with could not lock ...
    refusing to continue when another holder releases at the same
    instant; the acquire retries like the exclusive one does.
    - A released shared pin can no longer be revived by an orphaned
    keep-alive, and the sweep of abandoned holder records re-checks a
    record's age at the moment it removes it.

    No configuration or on-disk format changes. This update includes all
    changes since 0.9.16.

    Carries a patch raising the shared-lock retry bound, sent upstream.

    Advisory:
    https://github.com/berrym/btrfs-backup-ng/security/advisories/GHSA-5xvm-66c9-p5ph
    Full changelog:
    https://github.com/berrym/btrfs-backup-ng/blob/v0.9.19/CHANGELOG.md

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

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://bodhi.fedoraproject.org/updates/FEDORA-2026-a44f471fef");
  script_set_attribute(attribute:"solution", value:
"Update the affected btrfs-backup-ng package.");
  script_set_attribute(attribute:"risk_factor", value:"High");

  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:"2026/10/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/11/01");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:45");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:btrfs-backup-ng");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Fedora 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/RedHat/release", "Host/RedHat/rpm-list");

  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) || 'Fedora' >!< os_product) audit(AUDIT_OS_NOT, 'Fedora');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
if (! preg(pattern:"^45([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'Fedora 45', 'Fedora ' + os_version);

if (!get_kb_item('Host/RedHat/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 && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Fedora', cpu);

var constraints = [
  {
    'release': '45',
    'pkgs': [
      {'reference':'btrfs-backup-ng-0.9.20-1.fc45', '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, 'btrfs-backup-ng');
}