#VU63779 Out-of-bounds write in QEMU - CVE-2021-3713

Vulnerability identifier: #VU63779

Vulnerability risk: Medium

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-3713

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 local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in the UAS (USB Attached SCSI) device emulation of QEMU. A local user can perform a denial of service or escalate privileges on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

QEMU: 3.1.1.1 - 6.2.0

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1994640
https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
https://security.netapp.com/advisory/ntap-20210923-0006/
https://www.debian.org/security/2021/dsa-4980

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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.