Ubuntu update for samba

1) Out-of-bounds write

EUVDB-ID: #VU60186

Risk: High

CVSSv4.0: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/U:Amber]

CVE-ID: CVE-2021-44142

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: Yes

Description

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.

Mitigation

Update the affected package samba to the latest version.

Vulnerable software versions

Ubuntu: 18.04

samba (Ubuntu package): before 2:4.7.6+dfsg~ubuntu-0ubuntu2.28

CPE2.3

• cpe:2.3:o:canonical:ubuntu:18.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:samba_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-5260-2

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.