Ubuntu update for amd64-microcode

1) Use-after-free

EUVDB-ID: #VU78572

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-20593

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error in AMD Zen2 processors. A local user can trigger a use-after-free error and execute arbitrary code on the system.

Note, the vulnerability was dubbed Zenbleed.

Mitigation

Update the affected package amd64-microcode to the latest version.

Vulnerable software versions

Ubuntu: 16.04 - 23.04

amd64-microcode (Ubuntu package): before Ubuntu Pro

CPE2.3

• cpe:2.3:o:canonical:ubuntu:16.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:18.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:20.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:22.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:23.04:*:*:*:*:*:*:*
• cpe:2.3:a:canonical:amd64-microcode_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-6244-1

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.