Red Hat Enterprise Linux 7.6 update for samba

1) Out-of-bounds write

EUVDB-ID: #VU60186

Risk: High

CVSSv3.1: 8.9 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]

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

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.6

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.6

Red Hat Enterprise Linux Server - TUS: 7.6

Red Hat Enterprise Linux Server - AUS: 7.6

samba (Red Hat package): 4.8.3-4.el7

External links

http://access.redhat.com/errata/RHSA-2022:0663

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.