#VU63778 Release of invalid pointer or reference in QEMU - CVE-2021-3682

Vulnerability identifier: #VU63778

Vulnerability risk: Low

CVSSv4.0: 5.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-3682

CWE-ID: CWE-763

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
QEMU
Client/Desktop applications / Virtualization software

Vendor: QEMU

Description

The vulnerability allows a remote user to escalate privileges on the system.

The vulnerability exists in the USB redirector device emulation of QEMU when dropping packets during a bulk transfer from a SPICE client. A remote user can make QEMU call free() with faked heap chunk metadata to 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 - 6.1.0 rc2

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1989651
https://security.netapp.com/advisory/ntap-20210902-0006/
https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
https://www.debian.org/security/2021/dsa-4980

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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 Internet.

Is there known malware, which exploits this vulnerability?

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