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CVE-2021-43997

HIGHCVSS 7.8/10EPSS 0.32%

Last modified

CVE-2021-43997 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. FreeRTOS versions 10.2.0 through 10.4.5 do not prevent non-kernel code from calling the xPortRaisePrivilege internal function to raise privilege. FreeRTOS versions through 10.4.6 do not prevent a third party that has already independently gained the ability to execute injected code to achieve further privilege escalation by branching directly inside a FreeRTOS MPU API wrapper function with a manually crafted stack frame. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

Description

FreeRTOS versions 10.2.0 through 10.4.5 do not prevent non-kernel code from calling the xPortRaisePrivilege internal function to raise privilege. FreeRTOS versions through 10.4.6 do not prevent a third party that has already independently gained the ability to execute injected code to achieve further privilege escalation by branching directly inside a FreeRTOS MPU API wrapper function with a manually crafted stack frame. These issues affect ARMv7-M MPU ports, and ARMv8-M ports with MPU support enabled (i.e. configENABLE_MPU set to 1). These are fixed in V10.5.0 and in V10.4.3-LTS Patch 3.

Metrics

CVSS 3.1
7.8/10

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

EPSS Probability
0.32%

23.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersionsUpdate
AmazonFreertos>= 10.2.0, < 10.4.6—
AmazonFreertos10.4.3Patch1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-43997?
FreeRTOS versions 10.2.0 through 10.4.5 do not prevent non-kernel code from calling the xPortRaisePrivilege internal function to raise privilege. FreeRTOS versions through 10.4.6 do not prevent a third party that has already independently gained the ability to execute injected code to achieve further privilege escalation by branching directly inside a FreeRTOS MPU API wrapper function with a manually crafted stack frame. These issues affect ARMv7-M MPU ports, and ARMv8-M ports with MPU support enabled (i.e. configENABLE_MPU set to 1). These are fixed in V10.5.0 and in V10.4.3-LTS Patch 3.
How severe is CVE-2021-43997?
CVE-2021-43997 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.
How do I fix CVE-2021-43997?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-43997?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST