Bug 1858038 (CVE-2019-14560)

Summary: CVE-2019-14560 edk2: Function GetEfiGlobalVariable2() return value not checked in DxeImageVerificationHandler()
Product: [Other] Security Response Reporter: Pedro Sampaio <psampaio>
Component: vulnerabilityAssignee: Nobody <nobody>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: berrange, crobinso, kraxel, lersek, pbonzini, virt-maint, virt-maint
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 1858039, 1861743, 1858040, 1861744, 1910520    
Bug Blocks: 1858041    

Description Pedro Sampaio 2020-07-16 20:59:41 UTC 
A flaw was found in edk2. Function GetEfiGlobalVariable2() return value is not checked possibly leading to secure boot bypass if an attacker
can cause the API to fail.

References:

https://bugzilla.tianocore.org/show_bug.cgi?id=2167
Comment 1 Pedro Sampaio 2020-07-16 21:00:11 UTC 
Created edk2 tracking bugs for this issue:

Affects: epel-all [bug 1858039]
Affects: fedora-all [bug 1858040]
Comment 4 Riccardo Schirone 2020-07-29 12:52:06 UTC 
Proposed patch:
https://bugzilla.tianocore.org/attachment.cgi?id=405&action=diff
Comment 6 Riccardo Schirone 2020-07-29 13:12:56 UTC 
In function DxeImageVerificationHandler() there is a call to GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, ...) but the return value is not checked. If an attacker is able to cause the API to fail it would allow him to bypass secure boot.