Vulnerability Name:

CVE-2021-3981 (CCN-218384)

Assigned:2021-11-17
Published:2021-11-17
Updated:2023-02-12
Summary:A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue, as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released.
CVSS v3 Severity:3.3 Low (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)
2.9 Low (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): None
Availibility (A): None
3.3 Low (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)
2.9 Low (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): None
Availibility (A): None
3.3 Low (REDHAT CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)
2.9 Low (REDHAT Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): None
Availibility (A): None
CVSS v2 Severity:2.1 Low (CVSS v2 Vector: AV:L/AC:L/Au:N/C:P/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): None
1.7 Low (CCN CVSS v2 Vector: AV:L/AC:L/Au:S/C:P/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): None
Vulnerability Type:CWE-276
Vulnerability Consequences:Obtain Information
References:Source: MITRE
Type: CNA
CVE-2021-3981

Source: CCN
Type: Red Hat Bugzilla - Bug 2024170
(CVE-2021-3981) - CVE-2021-3981 grub2: Incorrect permission in grub.cfg allow unprivileged user to read the file content

Source: secalert@redhat.com
Type: Issue Tracking, Patch, Third Party Advisory
secalert@redhat.com

Source: XF
Type: UNKNOWN
grub2-cve20213981-info-disc(218384)

Source: CCN
Type: GRUB GIT Repository
grub-mkconfig: Restore umask for the grub.cfg

Source: secalert@redhat.com
Type: UNKNOWN
secalert@redhat.com

Source: secalert@redhat.com
Type: Third Party Advisory
secalert@redhat.com

Source: CCN
Type: GNU Web site
GRUB

Vulnerable Configuration:Configuration RedHat 1:
  • cpe:/o:redhat:enterprise_linux:8:*:*:*:*:*:*:*
    • Configuration RedHat 2:
  • cpe:/o:redhat:enterprise_linux:8::baseos:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/a:gnu:grub2:-:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:org.opensuse.security:def:7519
    P
    		grub2-2.06-150500.27.4 on GA media (Moderate)
    2023-06-12
    oval:org.opensuse.security:def:3480
    P
    		ecryptfs-utils-103-8.3.1 on GA media (Moderate)
    2022-06-28
    oval:org.opensuse.security:def:94573
    P
    		grub2-2.06-150400.9.9 on GA media (Moderate)
    2022-06-22
    oval:org.opensuse.security:def:95110
    P
    		grub2-x86_64-xen-2.06-150400.9.9 on GA media (Moderate)
    2022-06-22
    oval:org.opensuse.security:def:2943
    P
    		grub2-2.06-150400.9.9 on GA media (Moderate)
    2022-06-22
    oval:com.redhat.rhsa:def:20222110
    P
    		RHSA-2022:2110: grub2 security, bug fix, and enhancement update (Low)
    2022-05-10
    oval:org.opensuse.security:def:112365
    P
    		grub2-2.06-13.1 on GA media (Moderate)
    2022-01-17
    BACK
    gnu grub2 -