RHEL 7 : samba (Unpatched Vulnerability)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory samba. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(196676);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/11");

  script_cve_id(
    "CVE-2021-20316",
    "CVE-2021-43566",
    "CVE-2022-1615",
    "CVE-2022-2127",
    "CVE-2022-32742",
    "CVE-2022-32743",
    "CVE-2022-32746",
    "CVE-2023-4091",
    "CVE-2023-34966",
    "CVE-2023-34967",
    "CVE-2023-34968",
    "CVE-2023-42669"
  );

  script_name(english:"RHEL 7 : samba (Unpatched Vulnerability)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat 7 host is affected by multiple vulnerabilities that will not be patched.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 7 host has one or more packages installed that are affected by multiple
vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - samba: Symlink race error can allow directory creation outside of the exported share (CVE-2021-43566)

  - samba: Validated dnsHostname write right needs to be implemented (CVE-2022-32743)

  - A flaw was found in the way Samba handled file/directory metadata. This flaw allows an authenticated
    attacker with permissions to read or modify share metadata, to perform this operation outside of the
    share. (CVE-2021-20316)

  - In Samba, GnuTLS gnutls_rnd() can fail and give predictable random values. (CVE-2022-1615)

  - An out-of-bounds read vulnerability was found in Samba due to insufficient length checks in
    winbindd_pam_auth_crap.c. When performing NTLM authentication, the client replies to cryptographic
    challenges back to the server. These replies have variable lengths, and Winbind fails to check the lan
    manager response length. When Winbind is used for NTLM authentication, a maliciously crafted request can
    trigger an out-of-bounds read in Winbind, possibly resulting in a crash. (CVE-2022-2127)

  - A flaw was found in Samba. Some SMB1 write requests were not correctly range-checked to ensure the client
    had sent enough data to fulfill the write, allowing server memory contents to be written into the file (or
    printer) instead of client-supplied data. The client cannot control the area of the server memory written
    to the file (or printer). (CVE-2022-32742)

  - A flaw was found in the Samba AD LDAP server. The AD DC database audit logging module can access LDAP
    message values freed by a preceding database module, resulting in a use-after-free issue. This issue is
    only possible when modifying certain privileged attributes, such as userAccountControl. (CVE-2022-32746)

  - An infinite loop vulnerability was found in Samba's mdssvc RPC service for Spotlight. When parsing
    Spotlight mdssvc RPC packets sent by the client, the core unmarshalling function sl_unpack_loop() did not
    validate a field in the network packet that contains the count of elements in an array-like structure. By
    passing 0 as the count value, the attacked function will run in an endless loop consuming 100% CPU. This
    flaw allows an attacker to issue a malformed RPC request, triggering an infinite loop, resulting in a
    denial of service condition. (CVE-2023-34966)

  - A Type Confusion vulnerability was found in Samba's mdssvc RPC service for Spotlight. When parsing
    Spotlight mdssvc RPC packets, one encoded data structure is a key-value style dictionary where the keys
    are character strings, and the values can be any of the supported types in the mdssvc protocol. Due to a
    lack of type checking in callers of the dalloc_value_for_key() function, which returns the object
    associated with a key, a caller may trigger a crash in talloc_get_size() when talloc detects that the
    passed-in pointer is not a valid talloc pointer. With an RPC worker process shared among multiple client
    connections, a malicious client or attacker can trigger a process crash in a shared RPC mdssvc worker
    process, affecting all other clients this worker serves. (CVE-2023-34967)

  - A path disclosure vulnerability was found in Samba. As part of the Spotlight protocol, Samba discloses the
    server-side absolute path of shares, files, and directories in the results for search queries. This flaw
    allows a malicious client or an attacker with a targeted RPC request to view the information that is part
    of the disclosed path. (CVE-2023-34968)

  - A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with
    read-only permissions when the Samba VFS module acl_xattr is configured with acl_xattr:ignore system
    acls = yes. The SMB protocol allows opening files when the client requests read-only access but then
    implicitly truncates the opened file to 0 bytes if the client specifies a separate OVERWRITE create
    disposition request. The issue arises in configurations that bypass kernel file system permissions checks,
    relying solely on Samba's permissions. (CVE-2023-4091)

  - A vulnerability was found in Samba's rpcecho development server, a non-Windows RPC server used to test
    Samba's DCE/RPC stack elements. This vulnerability stems from an RPC function that can be blocked
    indefinitely. The issue arises because the rpcecho service operates with only one worker in the main RPC
    task, allowing calls to the rpcecho server to be blocked for a specified time, causing service
    disruptions. This disruption is triggered by a sleep() call in the dcesrv_echo_TestSleep() function
    under specific conditions. Authenticated users or attackers can exploit this vulnerability to make calls
    to the rpcecho server, requesting it to block for a specified duration, effectively disrupting most
    services and leading to a complete denial of service on the AD DC. The DoS affects all other services as
    rpcecho runs in the main RPC task. (CVE-2023-42669)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package
is installed.");
  script_set_attribute(attribute:"solution", value:
"The vendor has acknowledged the vulnerabilities but no solution has been provided. Refer to the vendor for remediation
guidance.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:N/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/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:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-43566");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2022-32743");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2022/01/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/05/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libldb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:samba");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:samba4");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Red Hat Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl", "redhat_repos.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm.inc');
include('rhel.inc');

if (!get_kb_item("global_settings/vendor_unpatched"))
exit(0, "Unpatched Vulnerabilities Detection not active.");

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'ge', os_version: os_ver, rhel_version: '7')) audit(AUDIT_OS_NOT, 'Red Hat 7.x', 'Red Hat ' + os_ver);

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 && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var constraints = [
  {
    'pkgs': [
      {'reference':'libldb', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'libldb', 'cves':['CVE-2022-32746']},
      {'reference':'samba', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'samba', 'cves':['CVE-2021-20316', 'CVE-2021-43566', 'CVE-2022-1615', 'CVE-2022-2127', 'CVE-2022-32742', 'CVE-2022-32743', 'CVE-2023-4091', 'CVE-2023-34966', 'CVE-2023-34967', 'CVE-2023-34968', 'CVE-2023-42669']}
    ]
  }
];


var flag = 0;
foreach var constraint_array ( constraints ) {
  var repo_relative_urls = NULL;
  var enterprise_linux_flag = rhel_repo_urls_has_content_dist_rhel(repo_urls:repo_relative_urls);
  foreach var pkg ( constraint_array['pkgs'] ) {
    var unpatched_pkg = NULL;
    var _release = NULL;
    var sp = NULL;
    var el_string = NULL;
    var rpm_spec_vers_cmp = NULL;
    var exists_check = NULL;
    var cves = NULL;
    if (!empty_or_null(pkg['unpatched_pkg'])) unpatched_pkg = pkg['unpatched_pkg'];
    if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (unpatched_pkg &&
        _release &&
        (!exists_check || rpm_exists(release:_release, rpm:exists_check)) &&
        unpatched_package_exists(release:_release, package:unpatched_pkg, cves: cves)) flag++;
  }
}

if (flag)
{
  var extra = NULL;
  security_report_v4(
      port       : 0,
      severity   : SECURITY_NOTE,
      extra      : unpatched_packages_report()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libldb / samba');
}