#VU72306 Out-of-bounds write in QEMU - CVE-2021-3638

Vulnerability identifier: #VU72306

Vulnerability risk: Medium

CVSSv4.0: 1.9 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-3638

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
QEMU
Client/Desktop applications / Virtualization software

Vendor: QEMU

Description

The vulnerability allows a malicious guest to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error in the ATI VGA device emulation of QEMU within the ati_2d_blt() routine while handling MMIO write operations. A malicious guest can crash the QEMU process on the host.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

QEMU: All versions

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1979858
https://ubuntu.com/security/CVE-2021-3638
https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg01682.html
https://security.netapp.com/advisory/ntap-20220407-0003/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GTVPHLLXJ65BUMFBUUZ35F3J632SLFRK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7J5IRXJYLELW7D43A75LOWRUE5EU54O/

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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.