CVE-2019-20908
An issue was discovered in drivers/firmware/efi/efi.c in the Linux kernel before 5.4. Incorrect access permissions for the efivar_ssdt ACPI variable could be used by attackers to bypass lockdown or
02 Description
An issue was discovered in drivers/firmware/efi/efi.c in the Linux kernel before 5.4. Incorrect access permissions for the efivar_ssdt ACPI variable could be used by attackers to bypass lockdown or
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 0.53% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 44.8% of scored records. A rank, not a probability.
- NVD base score
- 6.7 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2020-07-15 21:24Z6 YR AGO
- Last updated
- 2024-08-05 02:53Z2 YR AGO
- Reserved
- 2020-07-15
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-284Improper Access ControlPillar
- Data version
- 5.1
- Document digest
- ae4e3fa33409d9f5ba55ecdb2941a9e6301ffdf2053046db5d766c28417bda56
05 Affected products
06 References
- git.zx2c4.comhttps://git.zx2c4.com/american-unsigned-language/tree/american-unsigned-language.sh
- mailarchives.bentasker.co.ukhttps://mailarchives.bentasker.co.uk/Mirrors/OSSSec/2020/06-Jun/msg00035.html
- git.kernel.orghttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1957a85b0032a81e6482ca4aab883643b8dae06e
- cdn.kernel.orghttps://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4
- www.openwall.com[oss-security] 20200720 Re: Re: lockdown bypass on ubuntu 18.04's 4.15 kernel for loading unsigned moduleshttp://www.openwall.com/lists/oss-security/2020/07/20/6
- usn.ubuntu.comUSN-4427-1https://usn.ubuntu.com/4427-1/
- www.openwall.com[oss-security] 20200729 multiple secure boot grub2 and linux kernel vulnerabilitieshttp://www.openwall.com/lists/oss-security/2020/07/29/3
- www.openwall.com[oss-security] 20200730 Re: UEFI SecureBoot bypass fixes rolled out to kernels below radarhttp://www.openwall.com/lists/oss-security/2020/07/30/3
- www.openwall.com[oss-security] 20200730 UEFI SecureBoot bypass fixes rolled out to kernels below radarhttp://www.openwall.com/lists/oss-security/2020/07/30/2
- usn.ubuntu.comUSN-4439-1https://usn.ubuntu.com/4439-1/
- usn.ubuntu.comUSN-4426-1https://usn.ubuntu.com/4426-1/
- usn.ubuntu.comUSN-4440-1https://usn.ubuntu.com/4440-1/
- lists.opensuse.orgopenSUSE-SU-2020:1153http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00009.html
07 Fixed in
Debian 12
- linux Fixed in 5.2.6-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- linux Fixed in 5.2.6-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- linux Fixed in 5.2.6-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- linux-aws-hwe Fixed in 4.15.0-1079.83~16.04.1
- linux-azure Fixed in 4.15.0-1092.102~16.04.1
- linux-gcp Fixed in 4.15.0-1080.90~16.04.1
- linux-hwe Fixed in 4.15.0-112.113~16.04.1
- linux-hwe-edge No fix yet
- linux-oracle Fixed in 4.15.0-1050.54~16.04.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- linux Fixed in 4.15.0-112.113
- linux-aws Fixed in 4.15.0-1079.83
- linux-aws-5.0 No fix yet
- linux-aws-5.3 Fixed in 5.3.0-1032.34~18.04.2
- linux-azure No fix yet
- linux-azure-4.15 Fixed in 4.15.0-1092.102
- linux-azure-5.3 Fixed in 5.3.0-1034.35~18.04.1
- linux-azure-edge No fix yet
- linux-gcp No fix yet
- linux-gcp-4.15 Fixed in 4.15.0-1080.90
- linux-gcp-5.3 Fixed in 5.3.0-1032.34~18.04.1
- linux-gcp-edge No fix yet
- linux-gke-4.15 Fixed in 4.15.0-1066.69
- linux-gke-5.0 Fixed in 5.0.0-1045.46
- linux-gke-5.3 Fixed in 5.3.0-1032.34~18.04.1
- linux-hwe Fixed in 5.3.0-64.58~18.04.1
- linux-hwe-edge No fix yet
- linux-kvm Fixed in 4.15.0-1071.72
- linux-oem Fixed in 4.15.0-1093.103
- linux-oem-osp1 Fixed in 5.0.0-1065.70
- linux-oracle Fixed in 4.15.0-1050.54
- linux-oracle-5.0 No fix yet
- linux-oracle-5.3 Fixed in 5.3.0-1030.32~18.04.1
- linux-raspi2 Fixed in 4.15.0-1067.71
- linux-raspi2-5.3 Fixed in 5.3.0-1030.32~18.04.2
- linux-snapdragon Fixed in 4.15.0-1083.91
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- linux-azure-fde No fix yet
- linux-gke No fix yet
- linux-raspi2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- linux-intel-iot-realtime No fix yet
- linux-realtime No fix yet
- linux-riscv No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- linux-raspi-realtime No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- linux-azure Fixed in 4.15.0-1092.102~14.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 18.04 LTS
- linux-aws-fips Fixed in 4.15.0-2024.24Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 4.15.0-2006.7Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 4.15.0-1037.42Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 18.04 LTS
- linux-aws-fips No fix yet
- linux-azure-fips No fix yet
- linux-gcp-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.