Vulnerability in Gnu Grub2
CVE-2020-15705
GRUB2 fails to validate kernel signature when booted directly without shim, allowing secure boot to be bypassed. This only affects systems where the kernel signing certificate has been imported directly into the secure boot database and the GRUB image is booted directly without the use of shim. This issue affects GRUB2 version 2.04 and prior versions.
EPSS: 0.014 (69.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Gnu Grub2
- Microsoft Windows_10 — versions 1607, 1709, 1803
- Microsoft Windows_8.1
- Microsoft Windows_rt_8.1
- Microsoft Windows_server_2012 — versions r2
- Microsoft Windows_server_2016 — versions 1903, 1909, 2004
- Microsoft Windows_server_2019
- Canonical Ubuntu_linux — versions 14.04, 16.04, 18.04
- Debian Debian_linux — versions 10.0
- Opensuse Leap — versions 15.1, 15.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security@ubuntu.com (x_refsource_CONFIRM, Third Party Advisory)
- security@ubuntu.com (x_refsource_UBUNTU, vendor-advisory, Third Party Advisory)
- security@ubuntu.com (x_refsource_UBUNTU, vendor-advisory, Third Party Advisory)
- security@ubuntu.com (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security@ubuntu.com (x_refsource_CONFIRM, Patch, Third Party Advisory, Vendor Advisory)
- security@ubuntu.com (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
- security@ubuntu.com (vendor-advisory, Third Party Advisory, x_refsource_SUSE)
- security@ubuntu.com (vendor-advisory, Third Party Advisory, x_refsource_SUSE)
- security@ubuntu.com (x_refsource_CONFIRM, Mailing List, Third Party Advisory)
- security@ubuntu.com (x_refsource_CONFIRM, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2020-15705?
- CVE-2020-15705 is a medium-severity vulnerability in Gnu Grub2, classified under Improper Verification of Cryptographic Signature. CVSS score: 6.4/10. Published 2020-07-29.
- How severe is CVE-2020-15705?
- Medium severity. CVSS v3 base score is 6.4 out of 10.
- Is CVE-2020-15705 known to be exploited?
- 27 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.