CVE-2020-27339
Low
No strong exploitation signal.
CVSS base
6.7
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.3%
24.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-20
Published 2021-06-16 · modified 2026-08-11
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | H | High |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2021-06-16 — Published (NVD)
- 2026-08-11 — Last modified (NVD)
Description
In the kernel in Insyde InsydeH2O 5.x, certain SMM drivers did not correctly validate the CommBuffer and CommBufferSize parameters, allowing callers to corrupt either the firmware or the OS memory. The fixed versions for this issue in the AhciBusDxe, IdeBusDxe, NvmExpressDxe, SdHostDriverDxe, and SdMmcDeviceDxe drivers are 05.16.25, 05.26.25, 05.35.25, 05.43.25, and 05.51.25 (for Kernel 5.1 through 5.5).
Affected
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
- https://security.netapp.com/advisory/ntap-20220216-0005/
- https://www.insyde.com/security-pledge/SA-2021001
- https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
- https://security.netapp.com/advisory/ntap-20220216-0005/
- https://www.insyde.com/security-pledge/SA-2021001
- https://www.kb.cert.org/vuls/id/796611
- https://cert-portal.siemens.com/productcert/html/ssa-306654.html