SB2022020185 - Ubuntu update for samba
Published: February 1, 2022 Updated: September 22, 2022
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) 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.
2) 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.
3) 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.