#VU48590 Out-of-bounds write in Linux kernel - CVE-2020-14331

Vulnerability identifier: #VU48590

Vulnerability 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-2020-14331

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

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

The vulnerability exists due to a boundary error within the Linux kernel’s implementation of the invert video code on VGA consoles. A local user with can run a specially crafted program to call VT_RESIZE IOCTL, trigger an out-of-bounds write and execute arbitrary code on the target system with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.8 rc1 - 5.8 rc6

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1858679
https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
https://lists.openwall.net/linux-kernel/2020/07/29/234
https://www.openwall.com/lists/oss-security/2020/07/28/2

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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.