Secure boot bypass in edk2

1) Unchecked Return Value

EUVDB-ID: #VU83486

Risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-14560

CWE-ID: CWE-252 - Unchecked Return Value

Exploit availability: No

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to an unchecked return value within the DxeImageVerificationHandler() function in SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c. A local user can bypass the secure boot protection.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

edk2: before edk2-stable202305

External links

http://github.com/tianocore/edk2/pull/4155
http://bugzilla.redhat.com/show_bug.cgi?id=1858038
http://bugzilla.tianocore.org/show_bug.cgi?id=2167
http://github.com/tianocore/edk2/pull/4155/commits/2a18d5ce48dcadeb0ab44d463377c6ec90ddce56

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.