Firmware flaws could allow a malicious reflash, US CERT warns
Three vendors have released fixes for vulnerabilities found in the critical firmware used during a computer’s startup, according to an advisory from the U.S. Computer Emergency Readiness Team.
The vulnerabilities could allow an attacker to bypass a feature called Secure Boot, which verifies that firmware components carry a correct digital signature ensuring the software’s authenticity. The attacker could then replace the device’s firmware.
The flaws lie within some UEFI (unified extensible firmware interface) systems, the advisory said. UEFI is a firmware interface that was designed to improve upon BIOS.
A boot script within the UEFI S3 Resume path “resides in unprotected memory which can be tampered with by an attacker with access to physical memory,” the advisory said.