Improper access control in QEMU 9pfs

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU78780

Risk: Low

CVSSv4.0: 5.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-2861

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

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

The vulnerability exists due to an error in the 9p passthrough filesystem (9pfs) implementation in QEMU. A local user can escape from the exported 9p tree by creating and opening a device file in the shared folder.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

QEMU: All versions

CPE2.3

• cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*

External links

https://gitlab.com/qemu-project/qemu/-/commit/f6b0de53fb87ddefed348a39284c8e2f28dc4eda
https://bugzilla.redhat.com/show_bug.cgi?id=2219266
https://bugzilla.suse.com/show_bug.cgi?id=1212968

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.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to open a a specially crafted file.

The attacker would have to login to the system and perform certain actions in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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