IM
IronMonkey Threat Research

CVE-2020-27749 HIGH

Published: 2021-03-03 | Last Modified: 2024-11-21 | Status: Modified

Description

A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Additional Descriptions (1)

Se encontró un fallo en grub2 en versiones anteriores a 2.06. Los nombres de las variables presentes se expanden en la línea de comando proporcionada en sus correspondientes contenidos de variables, usando un búfer de la pila de 1kB para el almacenamiento temporal, sin una comprobación suficiente de límites. Si la función es llamada con una línea de comando que hace referencia a una variable con una carga útil suficientemente grande, es posible desbordar el búfer de la pila, corromper la trama de la pila y controlar una ejecución, lo que también podría omitir las protecciones de Secure Boot. La mayor amenaza de esta vulnerabilidad es la confidencialidad e integridad de los datos, así como la disponibilidad del sistema

CVSS Metrics

Base Score: 6.7 (MEDIUM)

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack VectorLOCAL
Attack ComplexityLOW
Privileges RequiredHIGH
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactHIGH
Integrity ImpactHIGH
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 0.8

Impact Score: 5.9

Base Score: 7.2 (HIGH)

AV:L/AC:L/Au:N/C:C/I:C/A:C

Access VectorLOCAL
Access ComplexityLOW
AuthenticationNONE
Confidentiality ImpactCOMPLETE
Integrity ImpactCOMPLETE
Availability ImpactCOMPLETE

Source: [email protected]

Type: Primary

Exploitability Score: 3.9

Impact Score: 10.0

Weaknesses

Source Type Description
[email protected] Secondary
en CWE-121
[email protected] Secondary
en CWE-787

Affected Products

Vendor Product Version Update Type
gnu grub2 * <built-in method update of dict object at 0x72a99868a2c0> Application
redhat enterprise_linux 7.0 <built-in method update of dict object at 0x72a9cc70ebc0> Operating System
redhat enterprise_linux 8.0 <built-in method update of dict object at 0x72a9b0d521c0> Operating System
redhat enterprise_linux_server_aus 7.2 <built-in method update of dict object at 0x72a9a3093240> Operating System
redhat enterprise_linux_server_aus 7.3 <built-in method update of dict object at 0x72a998688c80> Operating System
redhat enterprise_linux_server_aus 7.4 <built-in method update of dict object at 0x72a99868bf40> Operating System
redhat enterprise_linux_server_aus 7.6 <built-in method update of dict object at 0x72a9b0d51600> Operating System
redhat enterprise_linux_server_aus 7.7 <built-in method update of dict object at 0x72a949cf3580> Operating System
redhat enterprise_linux_server_aus 8.2 <built-in method update of dict object at 0x72a9b0d532c0> Operating System
redhat enterprise_linux_server_eus 7.6 <built-in method update of dict object at 0x72a99868b640> Operating System
redhat enterprise_linux_server_eus 7.7 <built-in method update of dict object at 0x72a9a3090e40> Operating System
redhat enterprise_linux_server_eus 8.1 <built-in method update of dict object at 0x72a9cc811300> Operating System
redhat enterprise_linux_server_tus 7.4 <built-in method update of dict object at 0x72a99868b040> Operating System
redhat enterprise_linux_server_tus 7.6 <built-in method update of dict object at 0x72a9b0d506c0> Operating System
redhat enterprise_linux_server_tus 7.7 <built-in method update of dict object at 0x72a9cc8b09c0> Operating System
redhat enterprise_linux_server_tus 8.2 <built-in method update of dict object at 0x72a9990f3840> Operating System
redhat enterprise_linux_workstation 7.0 <built-in method update of dict object at 0x72a9b0cc9d80> Operating System
fedoraproject fedora 33 <built-in method update of dict object at 0x72a9b0ccaac0> Operating System
fedoraproject fedora 34 <built-in method update of dict object at 0x72a9cc811740> Operating System
netapp ontap_select_deploy_administration_utility - <built-in method update of dict object at 0x72a9986891c0> Application

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_eus:7.7:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_eus:8.1:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_tus:7.4:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:*
Yes cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
Yes cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*
Notification
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