Vulnerability identifier: #VU51189

Vulnerability risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25647

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: No

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

Vendor: GNU

Description

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

The vulnerability exists due to a boundary error when processing untrusted input from USB device in grub_usb_device_initialize(). An attacker with physical access to the system can trigger an out-of-bounds write error with a malicious USB drive, bypass Secure Boot protection and execute arbitrary code on the system with elevated privileges.

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. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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