#VU63686 Resource management error in 1st Gen AMD EPYC Processors and 3rd Gen AMD EPYC Processors - CVE-2021-26342

Vulnerability identifier: #VU63686

Vulnerability risk: Low

CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-26342

CWE-ID: CWE-399

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
1st Gen AMD EPYC Processors
Hardware solutions / Firmware
3rd Gen AMD EPYC Processors
Hardware solutions / Firmware

Vendor: AMD

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to the CPU may fail to flush the Translation Lookaside Buffer (TLB) in SEV guest VMs. A local user can execute a particular sequence of operations that includes creation of a new virtual machine control block (VMCB) and disclose the SEV guest memory contents.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

1st Gen AMD EPYC Processors: before NaplesPI-SP3_1.0.0.H

3rd Gen AMD EPYC Processors: before MilanPI-SP3_1.0.0.7

---

External links
https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1028

---

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.