CVE-2018-5540: On F5 BIG-IP 13.0.0-13.0.1, 12.1.0-12.1.3.3, 11.6.0-11.6.3.1, or 11.5.1-11.5.6, Enterprise Manager 3.1.1, BIG-

Routine

MEDIUM 4.4UPGRADEUPGRADEDOWNGRADE

CVE-2018-5540 is a medium-severity flaw (CVSS 4.4) affecting big-ip domain name system, big-ip global traffic manager, enterprise manager. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

On F5 BIG-IP 13.0.0-13.0.1, 12.1.0-12.1.3.3, 11.6.0-11.6.3.1, or 11.5.1-11.5.6, Enterprise Manager 3.1.1, BIG-IQ Centralized Management 5.0.0-5.1.0, BIG-IQ Cloud and Orchestration 1.0.0, or F5 iWorkflow 2.1.0-2.3.0 the big3d process does not irrevocably minimize group privileges at start up.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.4 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-732
Published	2018-07-19
Last modified	2026-06-17

Publisher (CNA): F5 Networks · Vendor: f5

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

Am I affected?

Timeline

2018-07-19 14:29 UTCPublished CVE record published
2026-06-17 02:00 UTCUpdated Record last modified

f5 big-ip domain name system UPGRADE

Affected: >= 11.5.1 and <= 11.5.6 · >= 11.6.0 and <= 11.6.3.1 · >= 12.1.0 and <= 12.1.3.3 · >= 13.0.0 and <= 13.0.1

Fixed in: newer than 13.0.1

Safe to downgrade to: a release before 11.5.1

1. Check installed version

apt-cache policy big-ip-domain-name-system || rpm -q big-ip-domain-name-system || big-ip-domain-name-system --version

2. UPGRADE to newer than 13.0.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-domain-name-system

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-domain-name-system

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 11.5.1 (Debian / Ubuntu)

apt-cache madison big-ip-domain-name-system sudo apt install big-ip-domain-name-system=<VERSION_BEFORE_11.5.1> sudo apt-mark hold big-ip-domain-name-system

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

dnf --showduplicates list big-ip-domain-name-system sudo dnf downgrade big-ip-domain-name-system-<VERSION_BEFORE_11.5.1> sudo dnf versionlock add big-ip-domain-name-system

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.

f5 big-ip global traffic manager UPGRADE

Affected: >= 11.5.1 and <= 11.5.6 · >= 11.6.0 and <= 11.6.3.1 · >= 12.1.0 and <= 12.1.3.3 · >= 13.0.0 and <= 13.0.1

Fixed in: newer than 13.0.1

Safe to downgrade to: a release before 11.5.1

1. Check installed version

apt-cache policy big-ip-global-traffic-manager || rpm -q big-ip-global-traffic-manager || big-ip-global-traffic-manager --version

2. UPGRADE to newer than 13.0.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-global-traffic-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-global-traffic-manager

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 11.5.1 (Debian / Ubuntu)

apt-cache madison big-ip-global-traffic-manager sudo apt install big-ip-global-traffic-manager=<VERSION_BEFORE_11.5.1> sudo apt-mark hold big-ip-global-traffic-manager

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

dnf --showduplicates list big-ip-global-traffic-manager sudo dnf downgrade big-ip-global-traffic-manager-<VERSION_BEFORE_11.5.1> sudo dnf versionlock add big-ip-global-traffic-manager

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.

f5 enterprise manager DOWNGRADE

Affected: 3.1.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.1.1

1. Check installed version

apt-cache policy enterprise-manager || rpm -q enterprise-manager || enterprise-manager --version

2. No fixed release: DOWNGRADE to a release before 3.1.1 (Debian / Ubuntu)

apt-cache madison enterprise-manager sudo apt install enterprise-manager=<VERSION_BEFORE_3.1.1> sudo apt-mark hold enterprise-manager

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

dnf --showduplicates list enterprise-manager sudo dnf downgrade enterprise-manager-<VERSION_BEFORE_3.1.1> sudo dnf versionlock add enterprise-manager

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.

f5 big-iq centralized management UPGRADE

Affected: >= 5.0.0 and <= 5.1.0

Fixed in: newer than 5.1.0

Safe to downgrade to: a release before 5.0.0

1. Check installed version

apt-cache policy big-iq-centralized-management || rpm -q big-iq-centralized-management || big-iq-centralized-management --version

2. UPGRADE to newer than 5.1.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-iq-centralized-management

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-iq-centralized-management

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 5.0.0 (Debian / Ubuntu)

apt-cache madison big-iq-centralized-management sudo apt install big-iq-centralized-management=<VERSION_BEFORE_5.0.0> sudo apt-mark hold big-iq-centralized-management

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

dnf --showduplicates list big-iq-centralized-management sudo dnf downgrade big-iq-centralized-management-<VERSION_BEFORE_5.0.0> sudo dnf versionlock add big-iq-centralized-management

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.

f5 big-iq cloud and orchestration DOWNGRADE

Affected: 1.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy big-iq-cloud-and-orchestration || rpm -q big-iq-cloud-and-orchestration || big-iq-cloud-and-orchestration --version

2. No fixed release: DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison big-iq-cloud-and-orchestration sudo apt install big-iq-cloud-and-orchestration=<VERSION_BEFORE_1.0.0> sudo apt-mark hold big-iq-cloud-and-orchestration

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

dnf --showduplicates list big-iq-cloud-and-orchestration sudo dnf downgrade big-iq-cloud-and-orchestration-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add big-iq-cloud-and-orchestration

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.

f5 f5 iworkflow UPGRADE

Affected: >= 2.1.0 and <= 2.3.0

Fixed in: newer than 2.3.0

Safe to downgrade to: a release before 2.1.0

1. Check installed version

apt-cache policy f5-iworkflow || rpm -q f5-iworkflow || f5-iworkflow --version

2. UPGRADE to newer than 2.3.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade f5-iworkflow

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade f5-iworkflow

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 2.1.0 (Debian / Ubuntu)

apt-cache madison f5-iworkflow sudo apt install f5-iworkflow=<VERSION_BEFORE_2.1.0> sudo apt-mark hold f5-iworkflow

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

dnf --showduplicates list f5-iworkflow sudo dnf downgrade f5-iworkflow-<VERSION_BEFORE_2.1.0> sudo dnf versionlock add f5-iworkflow

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.

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-2018-5540?

big-ip domain name system: upgrade to newer than 13.0.1; big-ip global traffic manager: upgrade to newer than 13.0.1; enterprise manager: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-5540 being exploited?

CVE-2018-5540 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-2018-5540 affect?

CVE-2018-5540 affects big-ip domain name system, big-ip global traffic manager, enterprise manager. Severity is medium (CVSS 4.4). On F5 BIG-IP 13.0.0-13.0.1, 12.1.0-12.1.3.3, 11.6.0-11.6.3.1, or 11.5.1-11.5.6, Enterprise Manager 3.1.1, BIG-IQ Centralized Management 5.0.0-5.1.0, BIG-IQ Cloud and Orchestration 1.0.0, or F5 iWorkflow 2.1.0-2.3.0 the big3d process does no

How urgent is CVE-2018-5540?

Priority 24/100. No elevated risk signals yet.

Software pages

F5 BIG-IP vulnerabilities

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References

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