Modeling LabsApplication · Cisco
CVE-2023-20154
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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 conditions, the authentication mechanism would be bypassed and the attacker would be logged in as an administrator. A successful exploit could allow the attacker to obtain administrative privileges on the web interface of an affected server, including the ability to access and modify every simulation and all user-created data. To exploit this vulnerability, the attacker would need valid user credentials that are stored on the associated external authentication server. Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA vulnerability in Cisco Modeling Labs' external authentication mechanism allows an attacker with valid credentials on the external authentication server to bypass authentication and gain administrative access to the web interface. This is due to improper handling of certain messages returned by the external authentication server, enabling privilege escalation to full administrative control.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Modeling LabsApplication
>= 2.3, < 2.5.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Cisco Modeling Labs installation and versionLocate the CML installation and determine the installed version by checking the system software version or using the 'show version' command in the CML CLI or looking at the application version in the web interface.Affected if The installed version is >= 2.3.0 and < 2.5.1
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Determine if external authentication is enabledCheck the CML configuration for external authentication settings - typically found in the system settings, authentication settings, or user management section of the web interface or via CLI commands like 'show running-config' or 'show auth' to see if an external RADIUS or LDAP server is configured as the authentication source.Affected if External authentication (RADIUS, LDAP, or similar) is configured and enabled as the authentication mechanism
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Inspect user accounts for unauthorized admin accessReview the local user accounts in the CML web interface under User Management or Administration > Users. Look for newly created accounts with Administrator privileges, or accounts with elevated privileges that were not created by authorized administrators.Affected if There are unexpected administrator-level accounts or modifications to existing accounts that were not performed by known administrators
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Examine authentication and system logs for anomaly patternsReview CML system logs and authentication logs for entries indicating authentication bypass, privilege escalation, or successful admin logins from unexpected sources or at unusual times. Look for entries showing admin access immediately following external authentication events.Affected if Logs show admin access that bypassed normal authentication flow or privilege escalation events following external authentication responses
A system is affected if it runs Cisco Modeling Labs version 2.3.0 through 2.5.0 and has external authentication enabled, and should be checked for unauthorized admin account creation or anomalous admin login events in logs.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2.5.1
Apply Cisco software updates or implement available workarounds to address the authentication bypass. Ensure the external authentication server is properly secured and monitor for anomalous authentication patterns.
Cisco Modeling Labs version 2.5.1 or later
- 1. Identify the current installed version of Cisco Modeling Labs by accessing the web interface or using the CLI command 'show version'
- 2. Confirm the installed version is >= 2.3 and < 2.5.1 to confirm vulnerability
- 3. Review Cisco Modeling Labs release notes for version 2.5.1 to understand any upgrade considerations
- 4. Back up all simulation data and current configuration following Cisco backup procedures
- 5. Download Cisco Modeling Labs version 2.5.1 or later from the Cisco Software Download center
- 6. Apply the upgrade following the Cisco Modeling Labs upgrade documentation
- 7. After upgrade, verify the new version is running and test external authentication to confirm the vulnerability is resolved
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Modeling Labs
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-20154 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-20154 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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