#VU54317 Out-of-bounds read in QEMU - CVE-2021-20221

Vulnerability identifier: #VU54317

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-20221

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
QEMU
Client/Desktop applications / Virtualization software

Vendor: QEMU

Description

The vulnerability allows a local user to perform DoS attack.

The vulnerability exists due to an out-of-bounds heap buffer access in the ARM Generic Interrupt Controller emulator of QEMU. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

QEMU: 4.0.0 - 4.2.0

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External links
https://lists.debian.org/debian-lts-announce/2021/02/msg00024.html
https://bugzilla.redhat.com/show_bug.cgi?id=1924601
https://www.openwall.com/lists/oss-security/2021/02/05/1

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Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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