SB2022020193 - SUSE update for samba
Published: February 1, 2022
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 secuirty vulnerabilities.
1) Heap-based buffer overflow (CVE-ID: CVE-2020-27840)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing DNs inside bind requests. A remote attacker can send specially crafted LDAP request to Samba AD DC LDAP server, trigger heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
2) Out-of-bounds read (CVE-ID: CVE-2021-20277)
The vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary condition in ldb_handler_fold() function when processing multiple consecutive leading spaces within LDAP query. A remote user can send a specially crafted LDAP query, trigger out-of-bounds read error and crash the LDAP server.
3) Race condition (CVE-ID: CVE-2021-20316)
The vulnerability allows a remote user to escalate privileges on the system.
The vulnerability exists due to a race condition. A remote user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
4) NULL pointer dereference (CVE-ID: CVE-2021-36222)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5). A remote attacker can send a request containing a PA-ENCRYPTED-CHALLENGE padata element without using FAST and perform a denial of service (DoS) attack.
5) Link following (CVE-ID: CVE-2021-43566)
The vulnerability allows a remote user to bypass implemented security restrictions.
The vulnerability exists due to a symlink race condition when creating directories. A remote authenticated user can use SMB1 or NFS symlink race to create directories on the Unix filesystem outside of the share definition.
Successful exploitation of the vulnerability requites that the user has permissions to create folder in the target directory.
6) Link following (CVE-ID: CVE-2021-44141)
The vulnerability allows a remote user to gain access to sensitive information.
The vulnerability exists due to insecure link following. A remote user with ability to write files to the exported part of the file system under a share via SMB1 unix extensions or via NFS can create a symlink to determine if a file or directory exists in an area of the server file system not exported under the share definition.
7) Out-of-bounds write (CVE-ID: CVE-2021-44142)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error when processing EA metadata while opening files in smbd within the VFS Samba module (vfs_fruit). A remote attacker with ability to write to file's extended attributes can trigger an out-of-bounds write and execute arbitrary code with root privileges.
Note, the vulnerability in vfs_fruit exists in the default configuration of the fruit VFS module using fruit:metadata=netatalk or fruit:resource=file.
8) Insufficient verification of data authenticity (CVE-ID: CVE-2022-0336)
The vulnerability allows a local user to impersonate arbitrary services.
The vulnerability exists due to Samba AD DC relies only on SPN (service principals name) to identify services on the network. An attacker with ability to modify SPNs can bypass implemented protection and cause a denial of service condition by adding an SPN that matches an existing service or impersonate services on the network.
Remediation
Install update from vendor's website.