Remote code execution in QEMU

1) Use-after-free

EUVDB-ID: #VU64570

Risk: Medium

CVSSv3.1: 7 [CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3929

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote user to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the NVM Express Controller emulation in QEMU within the dma_buf_write() and dma_buf_read() function in hw/nvme/ctrl.c:nvme_tx(). A remote privileged user on the guest OS can trigger a use-after-free error and execute arbitrary code on the QEMU host.

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

Mitigation

Install updates from vendor's website.

Vulnerable software versions

QEMU: 6.0.0 - 6.2.0 rc2

External links

http://bugzilla.redhat.com/show_bug.cgi?id=2020298

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to open a a specially crafted file.

Is there known malware, which exploits this vulnerability?

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