CVE Tools
Track your stack

CVE-2020-27339

No known exploitation. EPSS puts it in the 22nd percentile. A vendor fix is available.

CVSS 3.16.7MediumEPSS percentile22nd0.3% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFixVendor fixNo build named by the sources

Published Updated Sources: CVE.org, NVD

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

What it is

From the CVE record

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).

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS22nd
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.3% chance of exploitation activity in the next 30 days, which ranks it in the 22nd percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

7 events over 1882 days, from the signal feeds we watch.

  1. Patch availablerecord updated
  2. Patch availablerecord updated
  3. Publishedweakness classified, att&ck mapped

Affected products

And 9 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

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

Scored 6.7 by NVD.

How it is reached

  • Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required HighRequires admin or elevated privileges
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 2 more references. See all after sign-in

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Siemens, not every advisory.

We use analytics cookies to see which pages and articles actually help people. Decline and none of them run — the site works the same. What we store