Vulnerability identifier: #VU51188

Vulnerability risk: Low

CVSSv3.1: 6 [CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-25632

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
grub
Universal components / Libraries / Libraries used by multiple products

Vendor: GNU

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to a use-after-free error when handling module unloads. A local privileged user can unload a kernel module, trigger a use-after-free error and bypass Secure Boot protection mechanism.

Mitigation
Install updates from vendor's repository.

Vulnerable software versions

grub: 2.00 - 2.06

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External links
http://seclists.org/oss-sec/2021/q1/189

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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. However, proof of concept for this vulnerability is available.