Secure Firewall Management CenterApplication · Cisco
CVE-2020-3553
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 · uneditedMultiple vulnerabilities in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. These vulnerabilities are due to insufficient validation of user-supplied input by the web-based management interface. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or access sensitive, browser-based information.
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 confidenceMultiple cross-site scripting (XSS) vulnerabilities in the web-based management interface of Cisco Firepower Management Center allow unauthenticated, remote attackers to inject malicious scripts via crafted links. The root cause is insufficient validation of user-supplied input in the web interface.
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
< 6.6.1CVSS 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
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 FMC product and versionLog into the Firepower Management Center web interface and navigate to the System > Updates page, or use the CLI and run 'show version' to display the installed software version.Affected if The installed version is less than 6.6.1 (for example, 6.5.0, 6.4.0, etc.)
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Confirm web management interface is enabledAccess the FMC web interface URL (typically https://<FMC_IP>/) in a browser or check if ports 443 or 8000 are listening on the FMC device using 'netstat -an | grep -E "(443|8000)"'Affected if The web-based management interface is accessible and responds to HTTP/HTTPS requests; this is required for the XSS vulnerability to be exploitable
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Verify no upstream filtering is in placeReview any network devices (proxies, load balancers, or WAFs) positioned in front of the FMC to determine if they perform input validation on requests destined for the FMC web interface.Affected if No input validation or WAF filtering is being applied to incoming requests targeting the FMC web interface, leaving it directly exposed to malicious script injection.
You are affected if your Cisco Firepower/Secure Firewall Management Center is running a version earlier than 6.6.1 and the web-based management interface is accessible without compensating input validation.
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.
From vendor data6.6.1
Apply Cisco's security updates/patches for FMC when available; as a temporary control, implement WAF rules to filter malicious input and educate users about not clicking untrusted links.
Fix this in Secure Firewall Management Center
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 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 $3,152.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3553 — 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-2020-3553 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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