#VU63787 Integer overflow in QEMU - CVE-2021-4206

Vulnerability identifier: #VU63787

Vulnerability risk: Low

CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-4206

CWE-ID: CWE-190

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 target system.

The vulnerability exists due to integer overflow in the cursor_alloc() function in the QXL display device emulation in QEMU. A privileged user can crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

QEMU: 3.1.50 - 6.2.0

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External links
https://starlabs.sg/advisories/21-4206/
https://bugzilla.redhat.com/show_bug.cgi?id=2036998
https://www.debian.org/security/2022/dsa-5133

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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.