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’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.
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 security feature bypass vulnerability exists in the way Key Distribution Center (KDC) determines if a service ticket can be used for delegation via Kerberos Constrained Delegation (KCD). To exploit the vulnerability, a compromised service that is configured to use KCD could tamper with a service ticket that is not valid for delegation to force the KDC to accept it.
The ownerset function in smbcacls.c in smbcacls in Samba 4.0.x before 4.0.16 and 4.1.x before 4.1.6 removes an ACL during use of a --chown or --chgrp option, which allows remote attackers to bypass intended access restrictions in opportunistic circumstances by leveraging an unintended administrative change.
Samba 3.x before 3.6.23, 4.0.x before 4.0.16, and 4.1.x before 4.1.6 does not enforce the password-guessing protection mechanism for all interfaces, which makes it easier for remote attackers to obtain access via brute-force ChangePasswordUser2 (1) SAMR or (2) RAP attempts.
The internal DNS server in Samba 4.x before 4.0.18 does not check the QR field in the header section of an incoming DNS message before sending a response, which allows remote attackers to cause a denial of service (CPU and bandwidth consumption) via a forged response packet that triggers a communication loop, a related issue to CVE-1999-0103.
Samba 3.6.6 through 3.6.23, 4.0.x before 4.0.18, and 4.1.x before 4.1.8, when a certain vfs shadow copy configuration is enabled, does not properly initialize the SRVSNAPSHOTARRAY response field, which allows remote authenticated users to obtain potentially sensitive information from process memory via a (1) FSCTLGETSHADOWCOPYDATA or (2) FSCTLSRVENUMERATESNAPSHOTS request.