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nessusThis script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.EULEROS_SA-2024-1436.NASL
HistoryMar 21, 2024 - 12:00 a.m.

EulerOS Virtualization 2.11.0 : samba (EulerOS-SA-2024-1436)

2024-03-2100:00:00
This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
4
samba
euleros virtualization
vulnerability
smb protocol
active directory
rodc
dos

7.5 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

7 High

AI Score

Confidence

High

0.002 Low

EPSS

Percentile

51.9%

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

  • 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 design flaw was found in Samba’s DirSync control implementation, which exposes passwords and secrets in Active Directory to privileged users and Read-Only Domain Controllers (RODCs). This flaw allows RODCs and users possessing the GET_CHANGES right to access all attributes, including sensitive secrets and passwords. Even in a default setup, RODC DC accounts, which should only replicate some passwords, can gain access to all domain secrets, including the vital krbtgt, effectively eliminating the RODC / DC distinction. Furthermore, the vulnerability fails to account for error conditions (fail open), like out- of-memory situations, potentially granting access to secret attributes, even under low-privileged attacker influence. (CVE-2023-4154)

  • 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 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 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(192377);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/03/21");

  script_cve_id("CVE-2023-4091", "CVE-2023-4154", "CVE-2023-42669");
  script_xref(name:"IAVA", value:"2023-A-0535");

  script_name(english:"EulerOS Virtualization 2.11.0 : samba (EulerOS-SA-2024-1436)");

  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 :

  - 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 design flaw was found in Samba's DirSync control implementation, which exposes passwords and secrets in
    Active Directory to privileged users and Read-Only Domain Controllers (RODCs). This flaw allows RODCs and
    users possessing the GET_CHANGES right to access all attributes, including sensitive secrets and
    passwords. Even in a default setup, RODC DC accounts, which should only replicate some passwords, can gain
    access to all domain secrets, including the vital krbtgt, effectively eliminating the RODC / DC
    distinction. Furthermore, the vulnerability fails to account for error conditions (fail open), like out-
    of-memory situations, potentially granting access to secret attributes, even under low-privileged attacker
    influence. (CVE-2023-4154)

  - 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 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-2024-1436
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?28312df2");
  script_set_attribute(attribute:"solution", value:
"Update the affected samba packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:N/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:H/I:N/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-2023-4154");

  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:"2023/10/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/03/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/03/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libsmbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libwbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-client");
  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-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-winbind");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-winbind-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:samba-winbind-modules");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:2.11.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei 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");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/uvp_version");

  exit(0);
}

include("rpm.inc");

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

var _release = get_kb_item("Host/EulerOS/release");
if (isnull(_release) || _release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "2.11.0") audit(AUDIT_OS_NOT, "EulerOS Virtualization 2.11.0");
if (!get_kb_item("Host/EulerOS/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$" && "aarch64" >!< cpu && "x86" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "x86" >!< cpu) audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

var flag = 0;

var pkgs = [
  "libsmbclient-4.15.3-4.h22.eulerosv2r11",
  "libwbclient-4.15.3-4.h22.eulerosv2r11",
  "samba-4.15.3-4.h22.eulerosv2r11",
  "samba-client-4.15.3-4.h22.eulerosv2r11",
  "samba-common-4.15.3-4.h22.eulerosv2r11",
  "samba-common-tools-4.15.3-4.h22.eulerosv2r11",
  "samba-libs-4.15.3-4.h22.eulerosv2r11",
  "samba-winbind-4.15.3-4.h22.eulerosv2r11",
  "samba-winbind-clients-4.15.3-4.h22.eulerosv2r11",
  "samba-winbind-modules-4.15.3-4.h22.eulerosv2r11"
];

foreach (var 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
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "samba");
}
VendorProductVersionCPE
huaweieuleroslibsmbclientp-cpe:/a:huawei:euleros:libsmbclient
huaweieuleroslibwbclientp-cpe:/a:huawei:euleros:libwbclient
huaweieulerossambap-cpe:/a:huawei:euleros:samba
huaweieulerossamba-clientp-cpe:/a:huawei:euleros:samba-client
huaweieulerossamba-commonp-cpe:/a:huawei:euleros:samba-common
huaweieulerossamba-common-toolsp-cpe:/a:huawei:euleros:samba-common-tools
huaweieulerossamba-libsp-cpe:/a:huawei:euleros:samba-libs
huaweieulerossamba-winbindp-cpe:/a:huawei:euleros:samba-winbind
huaweieulerossamba-winbind-clientsp-cpe:/a:huawei:euleros:samba-winbind-clients
huaweieulerossamba-winbind-modulesp-cpe:/a:huawei:euleros:samba-winbind-modules
Rows per page:
1-10 of 111

7.5 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

7 High

AI Score

Confidence

High

0.002 Low

EPSS

Percentile

51.9%