Grub2 up to 2.06 Configuration File grub.cfg default permission

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Grub2 up to 2.06. This affects an unknown part of the file grub.cfg of the component Configuration File Handler. Such manipulation leads to default permission. This vulnerability is documented as CVE-2021-3981. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Grub2 up to 2.06. Affected by this issue is an unknown functionality of the file grub.cfg of the component Configuration File Handler. The manipulation with an unknown input 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.

The weakness was released 03/11/2022 as 2024170. The advisory is shared for download at bugzilla.redhat.com. This vulnerability is handled as CVE-2021-3981 since 11/19/2021. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1222.

The vulnerability scanner Nessus provides a plugin with the ID 236599 (Alibaba Cloud Linux 3 : 0134: grub2, mokutil, shim, and shim-unsigned-x64 (ALINUX3-SA-2022:0134)), 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 vulnerability database at Tenable (236599). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Default permission
CWE: CWE-276 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 236599
Nessus Name: Alibaba Cloud Linux 3 : 0134: grub2, mokutil, shim, and shim-unsigned-x64 (ALINUX3-SA-2022:0134)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

11/19/2021 🔍
03/11/2022 +112 days 🔍
03/11/2022 +0 days 🔍
05/20/2025 +1166 days 🔍

Sourcesinfo

Advisory: 2024170
Status: Confirmed

CVE: CVE-2021-3981 (🔍)
GCVE (CVE): GCVE-0-2021-3981
GCVE (VulDB): GCVE-100-194636

Entryinfo

Created: 03/11/2022 09:29
Updated: 05/20/2025 18:58
Changes: 03/11/2022 09:29 (38), 03/13/2022 14:03 (1), 05/20/2025 18:58 (16)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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