Advisory Details

February 10th, 2021

QEMU Plan 9 File System Time-Of-Check Time-Of-Use Privilege Escalation Vulnerability

CVE ID	CVE-2021-20181
CVSS SCORE	7.5, AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
AFFECTED VENDORS	QEMU
AFFECTED PRODUCTS	QEMU
VULNERABILITY DETAILS	This vulnerability allows local attackers to execute arbitrary code on affected installations of QEMU. An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the handling of file descriptor maps. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the hypervisor.
ADDITIONAL DETAILS	QEMU has issued an update to correct this vulnerability. More details can be found at: https://bugs.launchpad.net/qemu/+bug/1911666
DISCLOSURE TIMELINE	2020-12-18 - Vulnerability reported to vendor 2021-02-10 - Coordinated public release of advisory
CREDIT	Ryota Shiga(@Ga_ryo_) of Flatt Security

BACK TO ADVISORIES