#VU63690 Out-of-bounds write in AMD products - CVE-2021-26312

Vulnerability identifier: #VU63690

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-26312

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
1st Gen AMD EPYC Processors
Hardware solutions / Firmware
2nd 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 escalate privileges on the system.

The vulnerability exists due to a boundary error caused by failure to flush the Translation Lookaside Buffer (TLB) of the I/O memory management unit (IOMMU). A local user can force an IO device to write to memory it should not be able to access and execute arbitrary code with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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

2nd Gen AMD EPYC Processors: before RomePI-SP3_1.0.0.D

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

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

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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.