CVE-2023-20154: A vulnerability in the external authentication mechanism of Cisco Modeling Labs could allow an unauthenticated

This month

CRITICAL 9.1REMOTEUPGRADE

CVE-2023-20154 is a critical-severity flaw (CVSS 9.1) affecting modeling labs. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability in the external authentication mechanism of Cisco Modeling Labs could allow an unauthenticated, remote attacker to access the web interface with administrative privileges. This vulnerability is due to the improper handling of certain messages that are returned by the associated external authentication server. An attacker could exploit this vulnerability by logging in to the web interface of an affected server. Under certain con

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-305
Published	2024-11-15
Last modified	2026-06-17

Publisher (CNA): Cisco Systems, Inc. · Vendor: cisco

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

Am I affected?

Timeline

2024-11-15 15:15 UTCPublished CVE record published
2026-06-17 05:29 UTCUpdated Record last modified

cisco modeling labs UPGRADE

Affected: >= 2.3 and < 2.5.1

Fixed in: 2.5.1

Safe to downgrade to: a release before 2.3

1. Check installed version

apt-cache policy modeling-labs || rpm -q modeling-labs || modeling-labs --version

2. UPGRADE to 2.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade modeling-labs

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade modeling-labs

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 2.3 (Debian / Ubuntu)

apt-cache madison modeling-labs sudo apt install modeling-labs=<VERSION_BEFORE_2.3> sudo apt-mark hold modeling-labs

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

dnf --showduplicates list modeling-labs sudo dnf downgrade modeling-labs-<VERSION_BEFORE_2.3> sudo dnf versionlock add modeling-labs

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-2023-20154?

modeling labs: upgrade to 2.5.1. Exact commands for each OS are on this page.

Is CVE-2023-20154 being exploited?

CVE-2023-20154 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-2023-20154 affect?

CVE-2023-20154 affects modeling labs. Severity is critical (CVSS 9.1). A vulnerability in the external authentication mechanism of Cisco Modeling Labs could allow an unauthenticated, remote attacker to access the web interface with administrative privileges. This vulnerability is due to the improper handlin

How urgent is CVE-2023-20154?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Cisco vulnerabilities

References

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