// For flags

CVE-2021-38578

edk2: integer underflow in SmmEntryPoint function leads to potential SMM privilege escalation

Severity Score

9.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Existing CommBuffer checks in SmmEntryPoint will not catch underflow when computing BufferSize.

Unas comprobaciones existentes de CommBuffer en SmmEntryPoint no detectan el desbordamiento cuando es calculado BufferSize

A flaw was found in edk2. A integer underflow in the SmmEntryPoint function leads to a write into the SMM region allowing a local attacker with administration privileges on the system to execute code within the SMM privileged context. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
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
Low
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-08-11 CVE Reserved
  • 2022-03-03 CVE Published
  • 2023-09-24 EPSS Updated
  • 2024-08-06 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-124: Buffer Underwrite ('Buffer Underflow')
  • 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
Tianocore
Search vendor "Tianocore"
Edk2
Search vendor "Tianocore" for product "Edk2"
<= 202202
Search vendor "Tianocore" for product "Edk2" and version " <= 202202"
-
Affected
Insyde
Search vendor "Insyde"
Kernel
Search vendor "Insyde" for product "Kernel"
5.0
Search vendor "Insyde" for product "Kernel" and version "5.0"
-
Affected
Insyde
Search vendor "Insyde"
Kernel
Search vendor "Insyde" for product "Kernel"
5.1
Search vendor "Insyde" for product "Kernel" and version "5.1"
-
Affected
Insyde
Search vendor "Insyde"
Kernel
Search vendor "Insyde" for product "Kernel"
5.2
Search vendor "Insyde" for product "Kernel" and version "5.2"
-
Affected
Insyde
Search vendor "Insyde"
Kernel
Search vendor "Insyde" for product "Kernel"
5.3
Search vendor "Insyde" for product "Kernel" and version "5.3"
-
Affected
Insyde
Search vendor "Insyde"
Kernel
Search vendor "Insyde" for product "Kernel"
5.4
Search vendor "Insyde" for product "Kernel" and version "5.4"
-
Affected
Insyde
Search vendor "Insyde"
Kernel
Search vendor "Insyde" for product "Kernel"
5.5
Search vendor "Insyde" for product "Kernel" and version "5.5"
-
Affected