CVE-2021-42059

An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.08.41, Kernel 5.1 before 05.16.41, Kernel 5.2 before 05.26.41, Kernel 5.3 before 05.35.41, and Kernel 5.4 before 05.42.20. A stack-based buffer overflow leads toarbitrary code execution in UEFI DisplayTypeDxe DXE driver.

Published: 2022-02-02 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-42059 is rated Low Risk (35.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.33%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-42059

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.07% 0.33% +0.27%
2 2025-04-21 0.20% 0.07% -0.13%
3 2025-03-30 0.20%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-42059

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
0.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
3.9 10.0 [email protected]

Weakness enumeration for CVE-2021-42059

Affected software / configurations for CVE-2021-42059

Vendor Product Version Raw CPE
insyde insydeh2o >= 5.0, < 5.08.41 cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*
insyde insydeh2o >= 5.1, < 5.16.41 cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*
insyde insydeh2o >= 5.2, < 5.26.41 cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*
insyde insydeh2o >= 5.3, < 5.35.41 cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*
insyde insydeh2o >= 5.4, < 5.42.20 cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*
siemens simatic_field_pg_m5_firmware cpe:2.3:o:siemens:simatic_field_pg_m5_firmware:*:*:*:*:*:*:*:*
siemens simatic_field_pg_m6_firmware cpe:2.3:o:siemens:simatic_field_pg_m6_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc127e_firmware cpe:2.3:o:siemens:simatic_ipc127e_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc227g_firmware cpe:2.3:o:siemens:simatic_ipc227g_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc277g_firmware cpe:2.3:o:siemens:simatic_ipc277g_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc327g_firmware cpe:2.3:o:siemens:simatic_ipc327g_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc377g_firmware cpe:2.3:o:siemens:simatic_ipc377g_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc427e_firmware cpe:2.3:o:siemens:simatic_ipc427e_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc477e_firmware cpe:2.3:o:siemens:simatic_ipc477e_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc627e_firmware cpe:2.3:o:siemens:simatic_ipc627e_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc647e_firmware cpe:2.3:o:siemens:simatic_ipc647e_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc677e_firmware cpe:2.3:o:siemens:simatic_ipc677e_firmware:*:*:*:*:*:*:*:*
siemens simatic_ipc847e_firmware cpe:2.3:o:siemens:simatic_ipc847e_firmware:*:*:*:*:*:*:*:*
siemens simatic_itp1000_firmware cpe:2.3:o:siemens:simatic_itp1000_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-42059

cvelogic Threat Intelligence