CVE-2018-5407: Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timi

This month

MEDIUM 4.7WATCHLISTMITIGATEMITIGATEUPGRADE

CVE-2018-5407 is a medium-severity flaw (CVSS 4.7) affecting ubuntu linux, debian linux, node.js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	4.7 (Medium)
Attack vector	Local
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	3.4% (top 11%)
CISA exploited list	No
Weakness	CWE-200, CWE-203
Published	2018-11-15
Last modified	2026-10-08

Publisher (CNA): CERT/CC · Vendor: canonical · debian · nodejs · openssl · oracle · tenable

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-11-15 21:29 UTCPublished CVE record published
2026-10-08 22:16 UTCUpdated Record last modified

canonical ubuntu linux MITIGATE

Affected: 14.04 · 16.04 · 18.04 · 18.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 14.04

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

debian debian linux MITIGATE

Affected: 8.0 · 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

nodejs node.js UPGRADE

Affected: < 6.14.4 · >= 8.0.0 and < 8.11.4 · >= 10.0.0 and < 10.9.0

Fixed in: 6.14.4, 8.11.4, 10.9.0

Safe to downgrade to: a release before 8.0.0

1. Check installed version

apt-cache policy node.js || rpm -q node.js || node.js --version

2. UPGRADE to 6.14.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade node.js

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade node.js

Note

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

3. If no update is available yet, DOWNGRADE to a release before 8.0.0 (Debian / Ubuntu)

apt-cache madison node.js sudo apt install node.js=<VERSION_BEFORE_8.0.0> sudo apt-mark hold node.js

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list node.js sudo dnf downgrade node.js-<VERSION_BEFORE_8.0.0> sudo dnf versionlock add node.js

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

openssl openssl UPGRADE

Affected: >= 1.0.2 and < 1.0.2q · >= 1.1.0 and < 1.1.0i

Fixed in: 1.0.2q, 1.1.0i

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy openssl || rpm -q openssl || openssl --version

2. UPGRADE to 1.0.2q (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade openssl

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openssl

Note

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

tenable nessus UPGRADE

Affected: < 8.1.1

Fixed in: 8.1.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy nessus || rpm -q nessus || nessus --version

2. UPGRADE to 8.1.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade nessus

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade nessus

Note

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

oracle api gateway DOWNGRADE

Affected: 11.1.2.4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 11.1.2.4.0

1. Check installed version

apt-cache policy api-gateway || rpm -q api-gateway || api-gateway --version

2. No fixed release: DOWNGRADE to a release before 11.1.2.4.0 (Debian / Ubuntu)

apt-cache madison api-gateway sudo apt install api-gateway=<VERSION_BEFORE_11.1.2.4.0> sudo apt-mark hold api-gateway

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list api-gateway sudo dnf downgrade api-gateway-<VERSION_BEFORE_11.1.2.4.0> sudo dnf versionlock add api-gateway

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Intel (Skylake / Kaby Lake) - 'PortSmash' CPU SMT Side-Channel

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-2018-5407?

ubuntu linux: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation; node.js: upgrade to 6.14.4, 8.11.4, 10.9.0. Exact commands for each OS are on this page.

Is CVE-2018-5407 being exploited?

CVE-2018-5407 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-2018-5407 affect?

CVE-2018-5407 affects ubuntu linux, debian linux, node.js. Severity is medium (CVSS 4.7). Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.

How urgent is CVE-2018-5407?

Priority 49/100. Public exploit reference; On your watchlist

Software pages

Node.js vulnerabilities · OpenSSL vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities

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References

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