AMD has disclosed information about a vulnerability (CVE-2025-54518) in processors based on Zen 2 microarchitecture that causes corruption of object code caches. Successful exploitation of the vulnerability allows CPU instructions to be executed at a higher privilege level. In practice, this issue potentially enables privilege escalation in the system, such as achieving code execution with kernel rights from user space or accessing the host environment from a virtual machine.
The vulnerability was identified by AMD employees, but exploitation details have not yet been provided. It has been stated that the issue is caused by improper isolation of shared resources during operations on CPU object code caches. By corrupting cache elements, an attacker can alter the instructions executed at a different privilege level.
The vulnerability is present only in AMD processors based on Zen 2 microarchitecture (Fam17h). The issue affects the Xen hypervisor and can be used to bypass isolation. Patches have been released for Xen branches from 4.17 to 4.21. A fix to block the vulnerability has also been submitted for inclusion in the Linux kernel.
In the desktop and mobile series AMD Ryzen 3000, 4000, 5000, 7020, 7030, and Threadripper PRO 3000 WX, the vulnerability was resolved last fall. In the embedded AMD Ryzen Embedded V2000 CPUs, the vulnerability was fixed at the end of December. The problem remains unaddressed in AMD EPYC 7002 series processors, and it is recommended to block it at the operating system level.
Source: opennet.ru
