Vulnérabilités de samba

DEBIAN-CVE-2026-109411

DEBIAN-CVE-2026-109411

Samba: ctdb fails to do integrity checking of received packets

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.

• Mettez à jour vers 2:4.24.5+dfsg-1

Samba: kpasswd service: kpasswd packet that contains malformed asn.1 might cause the server to access 6 bytes of unallocated memory leading server to crash

An out-of-bounds read flaw was found in Samba's Kerberos Key Distribution Center's (KDC) password change (kpasswd) service. When processing malformed ASN.1-encoded Kerberos password change request, Samba server miscalculates the structure size and attempts to read up to six bytes beyond the end of the allocated buffer. While this out-of-bounds read typically results in a harmless decryption failure, if the read hits unmapped memory, it causes the KDC process to crash. An authenticated attacker can send a specially crafted kpasswd request containing malformed ASN.1 data to trigger the out-of-bounds read, which may cause the KDC process to term

• Mettez à jour vers 2:4.24.5+dfsg-1

Samba: samba ad ldap compare filter injection and trusted-request confusion disclose protected attributes

A security flaw combining LDAP filter injection and improper authorization checks was found in Samba Active Directory Domain Controller (AD DC). When processing LDAP Compare requests, Samba fails to properly validate user-supplied attribute names and executes the resulting internal database search in a trusted context, bypassing normal Access Control List (ACL) enforcement. An authenticated low-privilege domain user can exploit these flaws to disclose confidential Active Directory attributes that would normally be inaccessible. The disclosed information may be leveraged to derive sensitive authentication material, potentially leading to privi

• Mettez à jour vers 2:4.24.5+dfsg-1

Samba: dns signing dos via tkey name cache exhaustion

A flaw was found in Samba's internal DNS server where unauthenticated TKEY registration requests were added to the TKEY name cache before being rejected. A remote, unauthenticated attacker can exploit this behavior by sending a large number of TKEY requests with arbitrary names, exhausting the cache and evicting legitimate TKEY entries. This can prevent legitimate TSIG authentication for signed DNS queries, resulting in a denial of service.

• Mettez à jour vers 2:4.24.5+dfsg-1

UBUNTU-CVE-2026-6949

TSIG packet with name compression can crash DNS. Incorrect size calculations when a TSIG record contains compressed names can lead to a large out-of-bounds write causing the server to crash.

• Mettez à jour vers 2:4.24.5+dfsg-1

UBUNTU-CVE-2026-58221

Samba AD authenticated LDAP access domain takeover. Samba AD low-privilege authenticated LDAP access allows modifications to internal LDB special DNs, which permits a domain takeover.

• Mettez à jour vers 2:4.24.5+dfsg-1

Samba-winbind: samba: pam_winbind mkhomedir chowns critical system paths without validation

A flaw was found in samba's pam_winbind. When mkhomedir is enabled, pam_winbind chowns the target account's home directory without validating the path is not a critical system directory such as /. On affected systems, accounts with / as their home directory (a common default for system accounts) can have this triggered not only by root, but by a non-root user holding a narrow sudo delegation to run commands as that account, causing ownership of / to change and resulting in severe denial of service (SSH, sudo, and package-manager failures). The change does not grant write access to / (which ships with restrictive 0555 permissions on RHEL), so

Samba: denial of service against ad dc wins server

A flaw was found in Samba’s WINS server component when running as an Active Directory Domain Controller. The WINS protocol handlers for certain request types did not properly validate incoming packets, allowing an unauthenticated remote attacker to trigger a NULL pointer dereference and crash the WINS service using specially crafted UDP packets.

• Mettez à jour vers 2:4.24.3+dfsg-1

Samba: remote code execution in samr

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.

• Mettez à jour vers 2:4.24.3+dfsg-1

Samba: missing access check on reparse point operations

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.

• Mettez à jour vers 2:4.24.3+dfsg-1

Samba: vfs_worm does not block directory modification

A flaw was found in Samba’s vfs_worm 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.

• Mettez à jour vers 2:4.24.3+dfsg-1

Samba: group policy certificate enrollment uses http:// without validation

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.

• Mettez à jour vers 2:4.24.3+dfsg-1

Samba: samba: remote code execution in printing subsystem via unescaped job description

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.

• Mettez à jour vers 2:4.24.3+dfsg-1

Samba: command injection in wins server hook script

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.

• Mettez à jour vers 2:4.23.2+dfsg-1

Samba: vfs_streams_xattr uninitialized memory write possible

A flaw was found in Samba, in the vfs_streams_xattr module, where uninitialized heap memory could be written into alternate data streams. This allows an authenticated user to read residual memory content that may include sensitive data, resulting in an information disclosure vulnerability.

• Mettez à jour vers 2:4.23.2+dfsg-1

Samba: smbd doesn't pick up group membership changes when re-authenticating an expired smb session

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.

• Mettez à jour vers 2:4.22.2+dfsg-1

Samba: check attribute access rights for ldap adds of computers

A vulnerability was found in Samba where a delegated administrator with permission to create objects in Active Directory can write to all attributes of the newly created object, including security-sensitive attributes, even after the object's creation. This issue occurs because the administrator owns the object due to the lack of an Access Control List (ACL) at the time of creation and later being recognized as the 'creator owner.' The retained significant rights of the delegated administrator may not be well understood, potentially leading to unintended privilege escalation or security risks.

• Mettez à jour vers 2:4.17.8+dfsg-1

Samba: ad dc password exposure to privileged users and rodcs

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

• Mettez à jour vers 2:4.19.1+dfsg-1

Samba: "rpcecho" development server allows denial of service via sleep() call on ad dc

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, requestin

• Mettez à jour vers 2:4.19.1+dfsg-1