#VU58813 Use-after-free in QEMU - CVE-2021-3748

Vulnerability identifier: #VU58813

Vulnerability risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-3748

CWE-ID: CWE-416

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
QEMU
Client/Desktop applications / Virtualization software

Vendor: QEMU

Description

The vulnerability allows a remote guest to compromise vulnerable system.

The vulnerability exists due to a use-after-free error when in the virtio-net device of QEMU. A malicious guest can trigger the use-after-free error and execute arbitrary code on the host system with QEMU privileges.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

QEMU: 6.0.0 - 6.1.0

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1998514
https://gitlab.com/qemu-project/qemu/-/issues/535

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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