GLSA-202402-28 : Samba: Multiple Vulnerabilities

critical Nessus Plugin ID 190761

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Description

The remote host is affected by the vulnerability described in GLSA-202402-28 (Samba: Multiple Vulnerabilities)

- An information leak vulnerability was discovered in Samba's LDAP server. Due to missing access control checks, an authenticated but unprivileged attacker could discover the names and preserved attributes of deleted objects in the LDAP store. (CVE-2018-14628)

- An out-of-bounds read vulnerability was found in Samba due to insufficient length checks in winbindd_pam_auth_crap.c. When performing NTLM authentication, the client replies to cryptographic challenges back to the server. These replies have variable lengths, and Winbind fails to check the lan manager response length. When Winbind is used for NTLM authentication, a maliciously crafted request can trigger an out-of-bounds read in Winbind, possibly resulting in a crash. (CVE-2022-2127)

- A vulnerability was found in Samba's SMB2 packet signing mechanism. The SMB2 packet signing is not enforced if an admin configured server signing = required or for SMB2 connections to Domain Controllers where SMB2 packet signing is mandatory. This flaw allows an attacker to perform attacks, such as a man-in- the-middle attack, by intercepting the network traffic and modifying the SMB2 messages between client and server, affecting the integrity of the data. (CVE-2023-3347)

- 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)

- An infinite loop vulnerability was found in Samba's mdssvc RPC service for Spotlight. When parsing Spotlight mdssvc RPC packets sent by the client, the core unmarshalling function sl_unpack_loop() did not validate a field in the network packet that contains the count of elements in an array-like structure. By passing 0 as the count value, the attacked function will run in an endless loop consuming 100% CPU. This flaw allows an attacker to issue a malformed RPC request, triggering an infinite loop, resulting in a denial of service condition. (CVE-2023-34966)

- A Type Confusion vulnerability was found in Samba's mdssvc RPC service for Spotlight. When parsing Spotlight mdssvc RPC packets, one encoded data structure is a key-value style dictionary where the keys are character strings, and the values can be any of the supported types in the mdssvc protocol. Due to a lack of type checking in callers of the dalloc_value_for_key() function, which returns the object associated with a key, a caller may trigger a crash in talloc_get_size() when talloc detects that the passed-in pointer is not a valid talloc pointer. With an RPC worker process shared among multiple client connections, a malicious client or attacker can trigger a process crash in a shared RPC mdssvc worker process, affecting all other clients this worker serves. (CVE-2023-34967)

- A path disclosure vulnerability was found in Samba. As part of the Spotlight protocol, Samba discloses the server-side absolute path of shares, files, and directories in the results for search queries. This flaw allows a malicious client or an attacker with a targeted RPC request to view the information that is part of the disclosed path. (CVE-2023-34968)

- 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.

Solution

All Samba users should upgrade to the latest version:

# emerge --sync # emerge --ask --oneshot --verbose >=net-fs/samba-4.18.9

Plugin Details

Severity: Critical

ID: 190761

File Name: gentoo_GLSA-202402-28.nasl

Version: 1.0

Type: local

Family: Gentoo Local Security Checks

Published: 2/20/2024

Updated: 2/20/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

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

CVSS Score Source: CVE-2023-3961

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

Vulnerability Information

CPE: cpe:/o:gentoo:linux, p-cpe:/a:gentoo:linux:samba

Required KB Items: Host/local_checks_enabled, Host/Gentoo/release, Host/Gentoo/qpkg-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2/19/2024

Vulnerability Publication Date: 1/17/2023

Reference Information

CVE: CVE-2018-14628, CVE-2022-2127, CVE-2023-3347, CVE-2023-34966, CVE-2023-34967, CVE-2023-34968, CVE-2023-3961, CVE-2023-4091, CVE-2023-4154, CVE-2023-42669, CVE-2023-42670

Detections

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