Linux Kernel up to 5.3 Lockdown/Secure Boot efi.c efivar_ssdt ACPI default permission
CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
5.2 | $0-$5k | 0.00 |
A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.3 (Operating System). This issue affects the function efivar_ssdt
of the file drivers/firmware/efi/efi.c of the component Lockdown/Secure Boot. The manipulation of the argument ACPI
as part of a Variable leads to a default permission vulnerability. Using CWE to declare the problem leads to CWE-276. During installation, installed file permissions are set to allow anyone to modify those files. Impacted is confidentiality, integrity, and availability. The summary by CVE is:
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 secure boot restrictions, aka CID-1957a85b0032.
The weakness was shared 07/15/2020. The identification of this vulnerability is CVE-2019-20908 since 07/15/2020. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1222 according to MITRE ATT&CK.
Upgrading to version 5.4 eliminates this vulnerability.
The entries VDB-265023, VDB-265024, VDB-265025 and VDB-265026 are related to this item.
Product
Type
Vendor
Name
Version
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔍VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 5.4VulDB Meta Temp Score: 5.3
VulDB Base Score: 4.2
VulDB Temp Score: 4.0
VulDB Vector: 🔍
VulDB Reliability: 🔍
NVD Base Score: 6.7
NVD Vector: 🔍
CVSSv2
AV | AC | Au | C | I | A |
---|---|---|---|---|---|
💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
---|---|---|---|---|---|
unlock | unlock | unlock | unlock | unlock | unlock |
unlock | unlock | unlock | unlock | unlock | unlock |
unlock | unlock | unlock | unlock | unlock | unlock |
VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍
NVD Base Score: 🔍
Exploiting
Class: Default permissionCWE: CWE-276 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍
Local: Yes
Remote: No
Availability: 🔍
Status: Not defined
EPSS Score: 🔍
EPSS Percentile: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍
0-Day | unlock | unlock | unlock | unlock |
---|---|---|---|---|
Today | unlock | unlock | unlock | unlock |
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔍
Upgrade: Kernel 5.4
Timeline
07/15/2020 🔍07/15/2020 🔍
07/16/2020 🔍
07/16/2020 🔍
Sources
Vendor: kernel.orgStatus: Not defined
CVE: CVE-2019-20908 (🔍)
See also: 🔍
Entry
Created: 07/16/2020 10:51Updated: 07/16/2020 10:56
Changes: 07/16/2020 10:51 (42), 07/16/2020 10:56 (18)
Complete: 🔍
Cache ID: 18:30B:103
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