CVE-2020-26541

kernel: security bypass in certs/blacklist.c and certs/system_keyring.c

Severity Score

6.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

The Linux kernel through 5.8.13 does not properly enforce the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. This affects certs/blacklist.c and certs/system_keyring.c.

El kernel de Linux versiones hasta 5.8.13, no aplica apropiadamente el mecanismo de protección Secure Boot Forbidden Signature Database (también se conoce como dbx). Esto afecta a los archivos certs/blacklist.c y certs/system_keyring.c

A flaw was found in the Linux kernel in certs/blacklist.c, When signature entries for EFI_CERT_X509_GUID are contained in the Secure Boot Forbidden Signature Database, the entries are skipped. This can cause a security threat and breach system integrity, confidentiality and even lead to a denial of service problem.

*Credits: N/A

CVSS Scores

Attack Vector

Local

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Local

Attack Complexity

Medium

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-10-02 CVE Reserved
2020-10-02 CVE Published
2024-02-05 EPSS Updated
2024-08-04 CVE Updated
2024-08-04 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

CAPEC

References (3)

URL	Tag	Source

URL	Date	SRC
https://lkml.org/lkml/2020/9/15/1871	2024-08-04

URL	Date	SRC

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2020-26541	2021-07-20
https://bugzilla.redhat.com/show_bug.cgi?id=1886285	2021-07-20

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				<= 5.8.13 Search vendor "Linux" for product "Linux Kernel" and version " <= 5.8.13"		-		Affected