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nessusThis script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.EULEROS_SA-2020-2199.NASL
HistoryOct 21, 2020 - 12:00 a.m.

EulerOS Virtualization 3.0.2.2 : samba (EulerOS-SA-2020-2199)

2020-10-2100:00:00
This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
34
samba
euleros
version 4.11.x
dns
ldap
vulnerability
kerberos
delegation
ad dc
s4u2self
ntlmssp

CVSS2

6.4

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:P/A:N

CVSS3

6.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

AI Score

6.8

Confidence

High

EPSS

0.01

Percentile

83.7%

According to the versions of the samba packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  • All Samba versions 4.x.x before 4.9.17, 4.10.x before 4.10.11 and 4.11.x before 4.11.3 have an issue, where the (poorly named) dnsserver RPC pipe provides administrative facilities to modify DNS records and zones. Samba, when acting as an AD DC, stores DNS records in LDAP. In AD, the default permissions on the DNS partition allow creation of new records by authenticated users. This is used for example to allow machines to self-register in DNS. If a DNS record was created that case-insensitively matched the name of the zone, the ldb_qsort() and dns_name_compare() routines could be confused into reading memory prior to the list of DNS entries when responding to DnssrvEnumRecords() or DnssrvEnumRecords2() and so following invalid memory as a pointer.(CVE-2019-14861)

  • All Samba versions 4.x.x before 4.9.17, 4.10.x before 4.10.11 and 4.11.x before 4.11.3 have an issue, where the S4U (MS-SFU) Kerberos delegation model includes a feature allowing for a subset of clients to be opted out of constrained delegation in any way, either S4U2Self or regular Kerberos authentication, by forcing all tickets for these clients to be non-forwardable. In AD this is implemented by a user attribute delegation_not_allowed (aka not-delegated), which translates to disallow-forwardable. However the Samba AD DC does not do that for S4U2Self and does set the forwardable flag even if the impersonated client has the not-delegated flag set.(CVE-2019-14870)

  • There is an issue in all samba 4.11.x versions before 4.11.5, all samba 4.10.x versions before 4.10.12 and all samba 4.9.x versions before 4.9.18, where the removal of the right to create or modify a subtree would not automatically be taken away on all domain controllers.(CVE-2019-14902)

  • All samba versions 4.9.x before 4.9.18, 4.10.x before 4.10.12 and 4.11.x before 4.11.5 have an issue where if it is set with ‘log level = 3’ (or above) then the string obtained from the client, after a failed character conversion, is printed. Such strings can be provided during the NTLMSSP authentication exchange. In the Samba AD DC in particular, this may cause a long-lived process(such as the RPC server) to terminate. (In the file server case, the most likely target, smbd, operates as process-per-client and so a crash there is harmless).(CVE-2019-14907)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(141682);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/14");

  script_cve_id(
    "CVE-2019-14861",
    "CVE-2019-14870",
    "CVE-2019-14902",
    "CVE-2019-14907"
  );

  script_name(english:"EulerOS Virtualization 3.0.2.2 : samba (EulerOS-SA-2020-2199)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing multiple security
updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the samba packages installed, the
EulerOS Virtualization installation on the remote host is affected by
the following vulnerabilities :

  - All Samba versions 4.x.x before 4.9.17, 4.10.x before
    4.10.11 and 4.11.x before 4.11.3 have an issue, where
    the (poorly named) dnsserver RPC pipe provides
    administrative facilities to modify DNS records and
    zones. Samba, when acting as an AD DC, stores DNS
    records in LDAP. In AD, the default permissions on the
    DNS partition allow creation of new records by
    authenticated users. This is used for example to allow
    machines to self-register in DNS. If a DNS record was
    created that case-insensitively matched the name of the
    zone, the ldb_qsort() and dns_name_compare() routines
    could be confused into reading memory prior to the list
    of DNS entries when responding to DnssrvEnumRecords()
    or DnssrvEnumRecords2() and so following invalid memory
    as a pointer.(CVE-2019-14861)

  - All Samba versions 4.x.x before 4.9.17, 4.10.x before
    4.10.11 and 4.11.x before 4.11.3 have an issue, where
    the S4U (MS-SFU) Kerberos delegation model includes a
    feature allowing for a subset of clients to be opted
    out of constrained delegation in any way, either
    S4U2Self or regular Kerberos authentication, by forcing
    all tickets for these clients to be non-forwardable. In
    AD this is implemented by a user attribute
    delegation_not_allowed (aka not-delegated), which
    translates to disallow-forwardable. However the Samba
    AD DC does not do that for S4U2Self and does set the
    forwardable flag even if the impersonated client has
    the not-delegated flag set.(CVE-2019-14870)

  - There is an issue in all samba 4.11.x versions before
    4.11.5, all samba 4.10.x versions before 4.10.12 and
    all samba 4.9.x versions before 4.9.18, where the
    removal of the right to create or modify a subtree
    would not automatically be taken away on all domain
    controllers.(CVE-2019-14902)

  - All samba versions 4.9.x before 4.9.18, 4.10.x before
    4.10.12 and 4.11.x before 4.11.5 have an issue where if
    it is set with 'log level = 3' (or above) then the
    string obtained from the client, after a failed
    character conversion, is printed. Such strings can be
    provided during the NTLMSSP authentication exchange. In
    the Samba AD DC in particular, this may cause a
    long-lived process(such as the RPC server) to
    terminate. (In the file server case, the most likely
    target, smbd, operates as process-per-client and so a
    crash there is harmless).(CVE-2019-14907)

Note that Tenable Network Security has extracted the preceding
description block directly from the EulerOS security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2020-2199
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b6e13936");
  script_set_attribute(attribute:"solution", value:
"Update the affected samba packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N");
  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:L/UI:N/S:U/C:L/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-14870");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2019-14902");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"patch_publication_date", value:"2020/10/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/10/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-client-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-common-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-common-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-libs");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:3.0.2.2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "3.0.2.2") audit(AUDIT_OS_NOT, "EulerOS Virtualization 3.0.2.2");
if (!get_kb_item("Host/EulerOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

flag = 0;

pkgs = ["samba-client-libs-4.7.1-9.h7",
        "samba-common-4.7.1-9.h7",
        "samba-common-libs-4.7.1-9.h7",
        "samba-common-tools-4.7.1-9.h7",
        "samba-libs-4.7.1-9.h7"];

foreach (pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "samba");
}

CVSS2

6.4

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:P/A:N

CVSS3

6.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

AI Score

6.8

Confidence

High

EPSS

0.01

Percentile

83.7%