#VU75985 Input validation error in AMD products - CVE-2021-46756

Vulnerability identifier: #VU75985

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-46756

CWE-ID: CWE-20

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 perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient input validation in SVC_MAP_USER_STACK in the ASP (AMD Secure Processor) bootloader. A local user with a malicious Uapp or ABL can send malformed or invalid syscall to the bootloader and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

1st Gen AMD EPYC Processors: before NaplesPI 1.0.0.J

2nd Gen AMD EPYC Processors: before RomePI 1.0.0.E

3rd Gen AMD EPYC Processors: before MilanPI 1.0.0.9

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External links
https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3001.html

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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.