Vulnerability Name:

CVE-2021-3418 (CCN-197617)

Assigned:2021-03-02
Published:2021-03-02
Updated:2021-03-22
Summary:If certificates that signed grub are installed into db, grub can be booted directly. It will then boot any kernel without signature validation. The booted kernel will think it was booted in secureboot mode and will implement lockdown, yet it could have been tampered. This flaw is a reintroduction of CVE-2020-15705 and only affects grub2 versions prior to 2.06 and upstream and distributions using the shim_lock mechanism.
CVSS v3 Severity:6.4 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H)
5.6 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
7.5 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H)
6.5 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Changed
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
CVSS v2 Severity:4.4 Medium (CVSS v2 Vector: AV:L/AC:M/Au:N/C:P/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Medium
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): Partial
6.0 Medium (CCN CVSS v2 Vector: AV:L/AC:H/Au:S/C:C/I:C/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): High
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): Complete
Integrity (I): Complete
Availibility (A): Complete
Vulnerability Type:CWE-281
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2021-3418

Source: MISC
Type: Issue Tracking, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1933757

Source: XF
Type: UNKNOWN
gnugrub-cve20213418-sec-bypass(197617)

Source: CCN
Type: GRUB GIT Repository
GNU GRUB2

Source: CCN
Type: oss-sec Mailing List, Tue, 2 Mar 2021 18:13:44 +0000
Multiple GRUB2 vulnerabilities

Source: CCN
Type: IBM Security Bulletin 6475265 (QRadar SIEM)
GRUB2 as used by IBM QRadar SIEM is vulnerable to arbitrary code execution

Vulnerable Configuration:Configuration 1:
  • cpe:/a:gnu:grub2:*:*:*:*:*:*:*:* (Version < 2.06)

    • Configuration CCN 1:
  • cpe:/a:gnu:grub2:-:*:*:*:*:*:*:*
  • AND
  • cpe:/a:ibm:qradar_security_information_and_event_manager:7.3.0:*:*:*:*:*:*:*
  • OR cpe:/a:ibm:qradar_security_information_and_event_manager:7.4.0:-:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    gnu grub2 *
    gnu grub2 -
    ibm qradar security information and event manager 7.3.0
    ibm qradar security information and event manager 7.4.0