#VU32927 Improper Verification of Cryptographic Signature in grub - CVE-2020-15705
Published: July 30, 2020
Vulnerability identifier: #VU32927
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2020-15705
CWE-ID: CWE-347
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerable software:
grub
grub
Software vendor:
GNU
GNU
Description
The vulnerability allows a local attacker to compromise the target system.
The vulnerability exists due to the affected software fails to validate kernel signature when booted directly without shim. An attacker with physical access can bypass secure boot.
Remediation
Install updates from vendor's website.
External links
- http://ubuntu.com/security/notices/USN-4432-1
- http://www.openwall.com/lists/oss-security/2020/07/29/3
- https://access.redhat.com/security/vulnerabilities/grub2bootloader
- https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
- https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot
- https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
- https://www.openwall.com/lists/oss-security/2020/07/29/3
- https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/
- https://www.suse.com/support/kb/doc/?id=000019673