CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
53.8%
The remote Fedora 37 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-fff0c857d6 advisory.
A path traversal vulnerability was identified in Samba when processing client pipe names connecting to Unix domain sockets within a private directory. Samba typically uses this mechanism to connect SMB clients to remote procedure call (RPC) services like SAMR LSA or SPOOLSS, which Samba initiates on demand.
However, due to inadequate sanitization of incoming client pipe names, allowing a client to send a pipe name containing Unix directory traversal characters (…/). This could result in SMB clients connecting as root to Unix domain sockets outside the private directory. If an attacker or client managed to send a pipe name resolving to an external service using an existing Unix domain socket, it could potentially lead to unauthorized access to the service and consequential adverse events, including compromise or service crashes. (CVE-2023-3961)
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)
A flaw was found in Samba. It is susceptible to a vulnerability where multiple incompatible RPC listeners can be initiated, causing disruptions in the AD DC service. When Samba’s RPC server experiences a high load or unresponsiveness, servers intended for non-AD DC purposes (for example, NT4-emulation classic DCs) can erroneously start and compete for the same unix domain sockets. This issue leads to partial query responses from the AD DC, causing issues such as The procedure number is out of range when using tools like Active Directory Users. This flaw allows an attacker to disrupt AD DC services.
(CVE-2023-42670)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2023-fff0c857d6
#
include('compat.inc');
if (description)
{
script_id(183931);
script_version("1.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/04/29");
script_cve_id(
"CVE-2023-3961",
"CVE-2023-4091",
"CVE-2023-4154",
"CVE-2023-42669",
"CVE-2023-42670"
);
script_xref(name:"IAVA", value:"2023-A-0535");
script_xref(name:"FEDORA", value:"2023-fff0c857d6");
script_name(english:"Fedora 37 : samba (2023-fff0c857d6)");
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 37 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2023-fff0c857d6 advisory.
- A path traversal vulnerability was identified in Samba when processing client pipe names connecting to
Unix domain sockets within a private directory. Samba typically uses this mechanism to connect SMB clients
to remote procedure call (RPC) services like SAMR LSA or SPOOLSS, which Samba initiates on demand.
However, due to inadequate sanitization of incoming client pipe names, allowing a client to send a pipe
name containing Unix directory traversal characters (../). This could result in SMB clients connecting as
root to Unix domain sockets outside the private directory. If an attacker or client managed to send a pipe
name resolving to an external service using an existing Unix domain socket, it could potentially lead to
unauthorized access to the service and consequential adverse events, including compromise or service
crashes. (CVE-2023-3961)
- 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)
- A flaw was found in Samba. It is susceptible to a vulnerability where multiple incompatible RPC listeners
can be initiated, causing disruptions in the AD DC service. When Samba's RPC server experiences a high
load or unresponsiveness, servers intended for non-AD DC purposes (for example, NT4-emulation classic
DCs) can erroneously start and compete for the same unix domain sockets. This issue leads to partial
query responses from the AD DC, causing issues such as The procedure number is out of range when using
tools like Active Directory Users. This flaw allows an attacker to disrupt AD DC services.
(CVE-2023-42670)
Note that Nessus has not tested for these issues 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-2023-fff0c857d6");
script_set_attribute(attribute:"solution", value:
"Update the affected 2:samba package.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
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:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-3961");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2023/10/10");
script_set_attribute(attribute:"patch_publication_date", value:"2023/10/11");
script_set_attribute(attribute:"plugin_publication_date", value:"2023/10/26");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:37");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:samba");
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:"Fedora Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");
exit(0);
}
include('rpm.inc');
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) || 'Fedora' >!< os_release) audit(AUDIT_OS_NOT, 'Fedora');
var os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
os_ver = os_ver[1];
if (! preg(pattern:"^37([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 37', 'Fedora ' + os_ver);
if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Fedora', cpu);
var pkgs = [
{'reference':'samba-4.17.12-1.fc37', 'release':'FC37', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'}
];
var flag = 0;
foreach package_array ( pkgs ) {
var reference = NULL;
var _release = NULL;
var sp = NULL;
var _cpu = NULL;
var el_string = NULL;
var rpm_spec_vers_cmp = NULL;
var epoch = NULL;
var allowmaj = NULL;
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (!empty_or_null(package_array['release'])) _release = package_array['release'];
if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
if (reference && _release) {
if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) 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, 'samba');
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-3961
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-4091
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-4154
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-42669
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-42670
bodhi.fedoraproject.org/updates/FEDORA-2023-fff0c857d6
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
53.8%