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
AI Score
Confidence
Low
EPSS
Percentile
46.4%
According to the versions of the samba packages installed, the EulerOS 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(188984);
script_version("1.0");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/16");
script_cve_id("CVE-2023-4091", "CVE-2023-4154", "CVE-2023-42669");
script_xref(name:"IAVA", value:"2023-A-0535");
script_name(english:"EulerOS 2.0 SP11 : samba (EulerOS-SA-2023-3286)");
script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing multiple security updates.");
script_set_attribute(attribute:"description", value:
"According to the versions of the samba packages installed, the EulerOS 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-2023-3286
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ae417900");
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:"2023/12/11");
script_set_attribute(attribute:"plugin_publication_date", value:"2024/01/16");
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:2.0");
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/sp");
script_exclude_keys("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 (_release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11");
var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(11)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11");
if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11", "EulerOS UVP " + uvp);
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", sp:"11", 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");
}
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
AI Score
Confidence
Low
EPSS
Percentile
46.4%