Ubuntu update for linux-aws-hwe

1) Out-of-bounds write

EUVDB-ID: #VU66590

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-2021-33656

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

Exploit availability: No

Description

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

The vulnerability exists due to a boundary error when setting font with malicous data by ioctl cmd PIO_FONT. A local user can trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

Mitigation

Update the affected package linux-aws-hwe to the latest version.

Vulnerable software versions

Ubuntu: 16.04

linux-image-aws-hwe (Ubuntu package): before 4.15.01140.151~16.04.1

linux-image-4.15.0-1140-aws-hwe (Ubuntu package): before 4.15.01140.151~16.04.1

CPE2.3

• cpe:2.3:o:canonical:ubuntu:16.04:*:*:*:*:*:*:*
• cpe:2.3:a:canonical:linux-image-aws-hwe_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:linux-image-4.15.0-1140-aws-hwe_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-5591-2

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.