// For flags

CVE-2020-27749

grub2: Stack buffer overflow in grub_parser_split_cmdline()

Severity Score

6.7
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

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

A flaw was found in grub2. 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.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-10-27 CVE Reserved
  • 2021-03-03 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-121: Stack-based Buffer Overflow
  • CWE-787: Out-of-bounds Write
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Gnu
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Grub2
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< 2.06
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-
Affected
Redhat
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Enterprise Linux
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7.0
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-
Affected
Redhat
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Enterprise Linux
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8.0
Search vendor "Redhat" for product "Enterprise Linux" and version "8.0"
-
Affected
Redhat
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Enterprise Linux Server Aus
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7.2
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-
Affected
Redhat
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Enterprise Linux Server Aus
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7.3
Search vendor "Redhat" for product "Enterprise Linux Server Aus" and version "7.3"
-
Affected
Redhat
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Enterprise Linux Server Aus
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7.4
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-
Affected
Redhat
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Enterprise Linux Server Aus
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7.6
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-
Affected
Redhat
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Enterprise Linux Server Aus
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7.7
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-
Affected
Redhat
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Enterprise Linux Server Aus
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8.2
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-
Affected
Redhat
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Enterprise Linux Server Eus
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7.6
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-
Affected
Redhat
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Enterprise Linux Server Eus
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7.7
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-
Affected
Redhat
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Enterprise Linux Server Eus
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8.1
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-
Affected
Redhat
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Enterprise Linux Server Tus
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7.4
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-
Affected
Redhat
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Enterprise Linux Server Tus
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7.6
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-
Affected
Redhat
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Enterprise Linux Server Tus
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7.7
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-
Affected
Redhat
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Enterprise Linux Server Tus
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8.2
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-
Affected
Redhat
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Enterprise Linux Workstation
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7.0
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-
Affected
Fedoraproject
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Fedora
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33
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-
Affected
Fedoraproject
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Fedora
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34
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-
Affected
Netapp
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Ontap Select Deploy Administration Utility
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--
Affected