Secure Firewall Management CenterApplication · Cisco
CVE-2023-20155
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 a logging API in Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause the device to become unresponsive or trigger an unexpected reload. This vulnerability could also allow an attacker with valid user credentials, but not Administrator privileges, to view a system log file that they would not normally have access to. This vulnerability is due to a lack of rate-limiting of requests that are sent to a specific API that is related to an FMC log. An attacker could exploit this vulnerability by sending a high rate of HTTP requests to the API. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to the FMC CPU spiking to 100 percent utilization or to the device reloading. CPU utilization would return to normal if the attack traffic was stopped before an unexpected reload was triggered.
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 the Cisco Firepower Management Center logging API lacks proper rate-limiting, allowing unauthenticated remote attackers to cause DoS via high-rate HTTP requests that spike CPU to 100% or trigger device reload. Additionally, authenticated non-Administrator users can view system log files they should not access due to insufficient authorization checks on the logging API endpoint.
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
Secure Firewall Management CenterApplication
>= 6.2.3, <= 6.2.3.18>= 6.4.0, <= 6.4.0.16>= 6.6.0, <= 6.6.7.1>= 7.0.0, <= 7.0.5>= 7.1.0, <= 7.1.0.3>= 7.2.0, <= 7.2.3.1>= 7.3.0, <= 7.3.1.1CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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 the product and versionLog into the Cisco Firepower Management Center web interface and navigate to Help > About, or use the CLI command 'show version' on the FMC device to determine the exact software version.Affected if The device is Cisco Secure Firewall Management Center (formerly Firepower Management Center) and the version falls within these ranges: 6.2.3 to 6.2.3.18, 6.4.0 to 6.4.0.16, 6.6.0 to 6.6.7.1, 7.0.0 to 7.0.5, 7.1.0 to 7.1.0.3, 7.2.0 to 7.2.3.1, or 7.3.0 to 7.3.1.1
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Verify logging API accessibilityCheck if the logging API endpoint is accessible externally or from untrusted networks. Review the FMC network configuration and access policies to determine if HTTP/HTTPS interfaces accepting connections from outside trusted admin networks are enabled.Affected if The FMC management interface is reachable from networks accessible to unauthenticated attackers, enabling them to send high-rate HTTP requests to the logging API endpoint.
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Check for rate limiting on logging APIReview the FMC configuration for any rate-limiting or connection throttling applied specifically to the logging API endpoint. Inspect the web server or proxy configuration in front of FMC if applicable.Affected if No rate-limiting mechanism is configured for the logging API endpoint, allowing an attacker to send high-volume requests that can cause CPU spike to 100% or trigger device reload.
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Review user roles and authorizationIn the FMC web interface, navigate to System > Users > User Management to list all configured users and their assigned roles. Identify users with non-Administrator access levels.Affected if Non-Administrator user accounts exist who could potentially access the logging API endpoint due to insufficient authorization checks, allowing unauthorized viewing of system log files.
Your environment is affected if you are running a vulnerable Cisco Secure Firewall Management Center version AND the logging API is network-accessible to unauthenticated or non-Administrator users without rate-limiting protection.
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 · scopedApply Cisco's patch for FMC when available; implement rate-limiting on the affected logging API endpoint and enforce proper authorization controls to restrict log file access to Administrator-level users only.
Upgrade to the first fixed version in your current branch (6.2.3.19+, 6.4.0.17+, 6.7.0+, or 7.0.6+) or the latest stable 7.x release
- 1. Identify the currently installed Cisco Secure Firewall Management Center version via the web interface (System > About > System Information) or CLI (show version)
- 2. Based on your current version branch, plan upgrade to the first fixed release: For 6.2.3.x upgrade to 6.2.3.19 or later; For 6.4.0.x upgrade to 6.4.0.17 or later; For 6.6.0.x upgrade to 6.7.0 or later; For 7.0.0.x upgrade to 7.0.6 or later
- 3. Before upgrading, backup the FMC configuration via the web interface (System > Backup) or using the backup.pl script
- 4. Download the appropriate FMC upgrade package from Cisco.com Software Download center
- 5. Upload the upgrade package via the FMC web interface (System > Updates > Product Updates)
- 6. Schedule a maintenance window as upgrades cause brief service interruptions
- 7. Install the update and verify the new version via System > About > System Information
- 8. After upgrade, confirm CPU utilization returns to normal and the device is stable
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Secure Firewall Management Center
Scoped from the published advisory
- Consultation6.0 h
- Implementation12.0 h
- Testing10.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,504.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-20155 — 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-2023-20155 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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