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CVE-2020-15705GRUB2: avoid loading unsigned kernels when GRUB is booted directly under secureboot without shim
- 6.4MediumCVSS base score
- 1.4%Exploitation in 30 daysEPSS · top 27% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By canonical
- 15 days later
· 15 days later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| canonicalCNA (assigner) | 3.1 | Medium6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.4% · top 27% of all CVEs (13 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.4.
Affected products
- affected 20.04 LTS – < 2.04-1ubuntu26.1
- affected 18.04 LTS – < 2.02-2ubuntu8.16
- affected 16.04 LTS – < 2.02~beta2-36ubuntu3.26
- affected 14.04 ESM – < 2.02~beta2-9ubuntu1.20
References
References20
- https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- http://ubuntu.com/security/notices/USN-4432-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://access.redhat.com/security/vulnerabilities/grub2bootloader (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/ (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- https://www.suse.com/support/kb/doc/?id=000019673 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- https://www.openwall.com/lists/oss-security/2020/07/29/3 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html (opens in a new tab)x_refsource_CONFIRMx_transferred
- [oss-security] 20200729 multiple secure boot grub2 and linux kernel vulnerabilities (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- https://security.netapp.com/advisory/ntap-20200731-0008/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- USN-4432-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- openSUSE-SU-2020:1280 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- openSUSE-SU-2020:1282 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- [oss-security] 20210302 Multiple GRUB2 vulnerabilities (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- GLSA-202104-05 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- [oss-security] 20210916 Containers-optimized OS (COS) membership in the linux-distros list (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [oss-security] 20210917 Re: Containers-optimized OS (COS) membership in the linux-distros list (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [oss-security] 20210920 Re: Containers-optimized OS (COS) membership in the linux-distros list (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2020-7691 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2020-15705)Record last updated .