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.

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 "aclxattr" is configured with "aclxattr: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.

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 "dcesrvechoTestSleep()" 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.

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.

MaxQueryDuration not honoured in Samba AD DC LDAP

A flaw was found in Samba’s vfsworm module. The module is intended to provide write-once, read-many (WORM) protections by preventing modification of files after a configurable grace period. Due to insufficient validation during rename operations, an authenticated user with write access to a share could overwrite a protected file by renaming a newly created file over the existing WORM-protected file.

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 slunpackloop() 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.

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.

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.

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 dallocvalueforkey() function, which returns the object associated with a key, a caller may trigger a crash in tallocgetsize() 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.

A flaw was found in Samba

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

A flaw was found in Samba's CTDB, the clustered database service used by Samba. Insufficient integrity validation of received CTDB protocol packets allows malformed packets containing invalid field lengths, improperly terminated strings, or inconsistent packet sizes to be processed without adequate bounds checking. A remote attacker with access to the CTDB private network may trigger a denial of service through process crashes or excessive memory consumption and, in limited cases, disclose adjacent memory contents.

An out-of-bounds read vulnerability was found in Samba due to insufficient length checks in winbinddpamauthcrap.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.

A delegated administrator who can create objects in Active Directory, can write to all attributes in that new object, including after the object is created because they own the object. This includes some security-sensitive attributes (less in Samba that in Windows).

Because these rights are due to there being no ACL at creation time and later being the nebulous 'creator owner', the implication that the delegated administrator retains significant rights may not be well understood.

Behaviour removing the implicit rights of creating users to write to all attributes is off by default in Samba and Windows (see CVE-2021-42291 )

(As mentioned in the bug, we developed some other protections for this that landed in the other CVEs, which is why this one didn't get the full security notice treatment).

The details of how to turn this protection on are at: https://support.microsoft.com/en-us/topic/kb5008383-active-directory-permissions-updates-cve-2021-42291-536d5555-ffba-4248-a60e-d6cbc849cde1

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A flaw was found in Samba’s certificate auto-enrollment Group Policy handling. When certificate auto-enrollment is enabled, Samba may retrieve a CA certificate over an unencrypted HTTP connection and install it into the local trust store without proper verification. An attacker with the ability to intercept or redirect network traffic could exploit this behavior to supply a malicious certificate authority certificate, potentially allowing interception or spoofing of trusted communications.

A flaw was found in the Samba printing subsystem. Samba passes the client-controlled job description string to the command configured with the "print command" setting via the "%J" substitution character without escaping shell meta characters. A remote attacker could exploit this vulnerability by sending a specially crafted print job description that contains unescaped shell characters. This could lead to remote code execution on the affected system.

A flaw was found in Samba. A remote attacker can exploit a misconfiguration in Samba file servers and classic domain controllers that use the "check password script" feature. If this script is configured with the %u substitution character, the client-controlled username is passed without proper escaping of shell meta-characters. This vulnerability allows an attacker to achieve remote command execution on the affected system. This issue primarily affects non-standard configurations where the "check password script" is used with %u and the samba-dcerpcd service is started as a system service.

A flaw was found in Samba’s handling of NTFS-style reparse points on shares configured with read only = yes. Due to missing SMB-layer access checks, authenticated users with underlying filesystem write permissions may create or delete reparse point metadata through SMB operations even on read-only exports. This could allow modification of SMB-visible file behavior, including converting files into symbolic links or other reparse point types.

A flaw was found in Samba, in the front-end WINS hook handling: NetBIOS names from registration packets are passed to a shell without proper validation or escaping. Unsanitized NetBIOS name data from WINS registration packets are inserted into a shell command and executed by the Samba Active Directory Domain Controller’s wins hook, allowing an unauthenticated network attacker to achieve remote command execution as the Samba process.

Windows Kerberos Elevation of Privilege Vulnerability

A flaw was found in the Samba AD LDAP server. The AD DC database audit logging module can access LDAP message values freed by a preceding database module, resulting in a use-after-free issue. This issue is only possible when modifying certain privileged attributes, such as userAccountControl.

Since the Windows Kerberos RC4-HMAC Elevation of Privilege Vulnerability was disclosed by Microsoft on Nov 8 2022 and per RFC8429 it is assumed that rc4-hmac is weak, Vulnerable Samba Active Directory DCs will issue rc4-hmac encrypted tickets despite the target server supporting better encryption (eg aes256-cts-hmac-sha1-96).

Windows Kerberos RC4-HMAC Elevation of Privilege Vulnerability

Netlogon RPC Elevation of Privilege Vulnerability

A flaw was found in Samba. The KDC accepts kpasswd requests encrypted with any key known to it. By encrypting forged kpasswd requests with its own key, a user can change other users' passwords, enabling full domain takeover.

PAC parsing in MIT Kerberos 5 (aka krb5) before 1.19.4 and 1.20.x before 1.20.1 has integer overflows that may lead to remote code execution (in KDC, kadmind, or a GSS or Kerberos application server) on 32-bit platforms (which have a resultant heap-based buffer overflow), and cause a denial of service on other platforms. This occurs in krb5pacparse in lib/krb5/krb/pac.c. Heimdal before 7.7.1 has "a similar bug."

A flaw was found in Samba. The security vulnerability occurs when KDC and the kpasswd service share a single account and set of keys, allowing them to decrypt each other's tickets. A user who has been requested to change their password, can exploit this flaw to obtain and use tickets to other services.

Samba does not validate the Validated-DNS-Host-Name right for the dNSHostName attribute which could permit unprivileged users to write it.