CVE-2020-27173: In vm-superio before 0.1.1, the serial console FIFO can grow to unlimited memory usage when data is sent to th

Q: How do I fix CVE-2020-27173?

vm-superio: upgrade to 0.1.1. Exact commands for each OS are on this page.

Q: Is CVE-2020-27173 being exploited?

CVE-2020-27173 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-27173 affect?

CVE-2020-27173 affects vm-superio. Severity is high (CVSS 7.5). In vm-superio before 0.1.1, the serial console FIFO can grow to unlimited memory usage when data is sent to the input source (i.e., standard input). This behavior cannot be reproduced from the guest side. When no rate limiting is in place,

Q: How urgent is CVE-2020-27173?

Priority 50/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2020-27173 is a high-severity flaw (CVSS 7.5) affecting vm-superio. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In vm-superio before 0.1.1, the serial console FIFO can grow to unlimited memory usage when data is sent to the input source (i.e., standard input). This behavior cannot be reproduced from the guest side. When no rate limiting is in place, the host can be subject to memory pressure, impacting all other VMs running on the same host.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.5% (top 25%)
CISA exploited list	No
Weakness	CWE-770
Published	2020-10-16
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: vm-superio project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-10-16 04:15 UTCPublished CVE record published
2026-06-17 03:08 UTCUpdated Record last modified

vm-superio project vm-superio UPGRADE

Affected: < 0.1.1

Fixed in: 0.1.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy vm-superio || rpm -q vm-superio || vm-superio --version

2. UPGRADE to 0.1.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade vm-superio

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade vm-superio

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-27173?

vm-superio: upgrade to 0.1.1. Exact commands for each OS are on this page.

Is CVE-2020-27173 being exploited?

CVE-2020-27173 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-27173 affect?

CVE-2020-27173 affects vm-superio. Severity is high (CVSS 7.5). In vm-superio before 0.1.1, the serial console FIFO can grow to unlimited memory usage when data is sent to the input source (i.e., standard input). This behavior cannot be reproduced from the guest side. When no rate limiting is in place,

How urgent is CVE-2020-27173?

Priority 50/100. High severity; Remotely exploitable, no login, no user action

References

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