grub2 up to 2.04 Kernel Signature Validator signature verification

CVSS Meta Temp Score
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CTI Interest Score
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6.4$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in grub2 up to 2.04. This issue affects some unknown processing of the component Kernel Signature Validator. This manipulation causes signature verification. This vulnerability appears as CVE-2020-15705. The attack requires local access. There is no available exploit.

Detailsinfo

A vulnerability was found in grub2 up to 2.04. It has been declared as critical. Affected by this vulnerability is an unknown code of the component Kernel Signature Validator. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was presented 07/29/2020 (Website). It is possible to read the advisory at lists.gnu.org. This vulnerability is known as CVE-2020-15705 since 07/14/2020. The exploitation appears to be difficult. Attacking locally is a requirement. Additional levels of successful authentication are necessary for exploitation. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 236631 (Alibaba Cloud Linux 3 : 0026: grub2 (ALINUX3-SA-2021:0026)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (236631) and CERT Bund (WID-SEC-2022-0553). See VDB-159164 and VDB-159165 for similar entries. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Ubuntu Linux
  • IBM Security Guardium
  • Open Source Grub
  • Debian Linux
  • Red Hat Enterprise Linux
  • Microsoft Windows
  • Cisco Identity Services Engine (ISE)
  • SUSE Linux
  • Cisco Router
  • Oracle Linux
  • HPE ProLiant
  • Gentoo Linux
  • Palo Alto Networks PAN-OS
  • Avaya Aura Communication Manager
  • Avaya Aura Session Manager
  • Avaya Aura Application Enablement Services
  • Avaya Aura System Manager
  • Avaya Web License Manager
  • Aruba ArubaOS

Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.4

VulDB Base Score: 6.4
VulDB Temp Score: 6.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.4
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 236631
Nessus Name: Alibaba Cloud Linux 3 : 0026: grub2 (ALINUX3-SA-2021:0026)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

07/14/2020 🔍
07/29/2020 +15 days 🔍
07/30/2020 +1 days 🔍
03/18/2026 +2057 days 🔍

Sourcesinfo

Advisory: lists.gnu.org
Status: Not defined
Confirmation: 🔍

CVE: CVE-2020-15705 (🔍)
GCVE (CVE): GCVE-0-2020-15705
GCVE (VulDB): GCVE-100-159163
CERT Bund: WID-SEC-2022-0553 - Grub2: Mehrere Schwachstellen ermöglichen Umgehen von Sicherheitsvorkehrungen

See also: 🔍

Entryinfo

Created: 07/30/2020 16:48
Updated: 03/18/2026 18:10
Changes: 07/30/2020 16:48 (38), 07/30/2020 16:53 (11), 11/06/2020 15:11 (1), 11/06/2020 15:18 (1), 05/19/2025 20:54 (17), 03/18/2026 18:10 (7)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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