Buffer overflow in AMD products - CVE-2021-26386

Vulnerability identifier: #VU63735

CSH Severity: Low

CVSS v4.0: 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-2021-26386

CWE-ID: CWE-119

Exploitation vector: Local access

Exploit availability: No public exploit available

Vendor: AMD

Affected software:
AMD Ryzen 2000 series Desktop processor
AMD Ryzen 3000 Series Desktop processor
AMD Ryzen 5000 Series Desktop processor
AMD Ryzen 5000 Series Desktop processor with Radeon graphics
2nd Gen AMD Ryzen Threadripper processors
3rd Gen AMD Ryzen Threadripper processors
AMD Ryzen Threadripper PRO processors
AMD Ryzen 2000 Series Mobile processor
AMD Ryzen 3000 Series Mobile processor
2nd Gen AMD Ryzen Mobile processor with Radeon graphics
AMD Athlon 3000 Series Mobile processors with Radeon Graphics
AMD Ryzen 3000 Series Mobile processor with Radeon graphics
AMD Ryzen 5000 Series Mobile processor with Radeon graphics

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error. A malicious or compromised UApp or ABL can issue a malformed system call to the Stage 2 Bootloader, trigger memory corruption and execute arbitrary code with elevated privileges.

Install updates from vendor's website.

• https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1027