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EulerOS 2.0 SP11 : samba (EulerOS-SA-2023-3258)

medium Nessus Plugin ID 188849

Synopsis

The remote EulerOS host is missing multiple security updates.

Description

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.

Solution

Update the affected samba packages.

See Also

http://www.nessus.org/u?20217ca8

Plugin Details

Severity: Medium

ID: 188849

File Name: EulerOS_SA-2023-3258.nasl

Version: 1.0

Type: local

Published: 1/16/2024

Updated: 1/16/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:N/A:N

CVSS Score Source: CVE-2023-4154

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:huawei:euleros:libsmbclient, p-cpe:/a:huawei:euleros:libwbclient, p-cpe:/a:huawei:euleros:samba, p-cpe:/a:huawei:euleros:samba-client, p-cpe:/a:huawei:euleros:samba-common, p-cpe:/a:huawei:euleros:samba-common-tools, p-cpe:/a:huawei:euleros:samba-libs, p-cpe:/a:huawei:euleros:samba-winbind, p-cpe:/a:huawei:euleros:samba-winbind-clients, p-cpe:/a:huawei:euleros:samba-winbind-modules, cpe:/o:huawei:euleros:2.0

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/EulerOS/release, Host/EulerOS/rpm-list, Host/EulerOS/sp

Excluded KB Items: Host/EulerOS/uvp_version

Exploit Ease: No known exploits are available

Patch Publication Date: 12/11/2023

Vulnerability Publication Date: 10/10/2023

Reference Information

CVE: CVE-2023-4091, CVE-2023-4154, CVE-2023-42669

IAVA: 2023-A-0535