Vulnerability in Amazon Freertos
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (24.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Amazon Freertos — versions 10.4.3
Public proof-of-concept exploits
References
- github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V10.4.3-LTS-Patch-2 (Third Party Advisory, Release Notes)
- github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V10.4.6 (Third Party Advisory, Release Notes)
- github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V10.5.0
- github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V10.4.3-LTS-Patch-3
Frequently asked questions
- What is CVE-2021-43997?
- CVE-2021-43997 is a high-severity vulnerability in Amazon Freertos. CVSS score: 7.8/10. Published 2021-11-17.
- How severe is CVE-2021-43997?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2021-43997 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.