Use-after-free in Linux kernel fbdev core driver

1) Use-after-free

EUVDB-ID: #VU90130

Risk: Low

CVSSv3.1: 7.7 [AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-47338

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 within the fb_set_var() function in drivers/video/fbdev/core/fbmem.c. A local user can escalate privileges on the system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

External links

http://git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa
http://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8
http://git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693
http://git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126
http://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc

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.