#VU63781 NULL pointer dereference in QEMU - CVE-2021-4158

Vulnerability identifier: #VU63781

Vulnerability risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-4158

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
QEMU
Client/Desktop applications / Virtualization software

Vendor: QEMU

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in the ACPI code of QEMU when handling certain values. A privileged user can crash the QEMU process on the host, resulting in a denial of service condition.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

QEMU: 3.1.50 - 6.2.0

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External links
https://ubuntu.com/security/notices/USN-5307-1
https://bugzilla.redhat.com/show_bug.cgi?id=2035002
https://gitlab.com/qemu-project/qemu/-/issues/770

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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.