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Firepower Management Center Virtual ApplianceApplication · Cisco

CVE-2021-34764

MEDIUM · 6.1 CVSS v3.1 Published 2021-10-27
Fix available
A fix is available. Upgrade to 6.4.0.13 / 6.6.5 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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 · unedited
Multiple vulnerabilities in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an attacker to execute a cross-site scripting (XSS) attack or an open redirect attack. For more information about these vulnerabilities, see the Details section of this advisory.

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 · moderate confidence

Multiple cross-site scripting (XSS) and open redirect vulnerabilities in the web-based management interface of Cisco Firepower Management Center allow attackers to inject malicious scripts or redirect users to attacker-controlled sites via crafted URLs in the management UI.

MitigationApply the relevant Cisco FMC software update/patch when available; until patched, restrict access to the FMC management interface to trusted networks only and train users to avoid clicking untrusted links.

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
Firepower Management Center Virtual ApplianceApplication
Affected:= 6.1.0= 6.2.0= 6.2.3= 6.3.0= 6.4.0= 6.5.0= 6.6.0= 6.6.1= 6.7.0= 7.0.0= 7.1.0
Secure Firewall Threat DefenseApplication
Affected:< 6.4.0.13>= 6.5.0, < 6.6.5>= 6.7.0, < 6.7.0.3
Sourcefire Defense CenterApplication
Affected:= 6.1.0= 6.2.0= 6.2.3= 6.3.0= 6.4.0= 6.5.0= 6.6.0= 6.6.1= 6.7.0= 7.0.0= 7.1.0

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed Cisco product
    Log into the device CLI or check the system inventory to determine if the system is running Cisco Firepower Management Center (FMC), Firepower Threat Defense (FTD), or Sourcefire Defense Center. Use 'show version' or check the management interface login page banner for product identification.
    Affected if The product is any of the three affected: FMC Virtual Appliance, FTD, or Sourcefire Defense Center
  2. Determine the software version
    Run 'show version' from the CLI or check the About page in the web-based management interface to obtain the exact installed version number.
    Affected if The version matches one in the affected lists: FMC/Sourcefire = 6.1.0, 6.2.0, 6.2.3, 6.3.0, 6.4.0, 6.5.0, 6.6.0, 6.6.1, 6.7.0, 7.0.0, or 7.1.0; FTD = < 6.4.0.13, >= 6.5.0 and < 6.6.5, or >= 6.7.0 and < 6.7.0.3
  3. Confirm the web management interface is enabled
    Check if the FMC web UI (HTTPS on port 443 or 8443) is accessible and operational. Verify by attempting to reach the management interface URL or checking listener status with 'show http-server' or equivalent commands.
    Affected if The web-based management interface is enabled and reachable on the network
  4. Verify network accessibility of management interface
    Determine if the management interface is exposed to untrusted networks by reviewing interface assignments, ACLs, and the 'system settings web interface' configuration.
    Affected if The management interface is accessible from networks outside the trusted administrative zone

The environment is affected if running any of the listed product versions with the web-based management interface enabled and accessible, particularly from untrusted networks.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 6.4.0.13 / 6.6.5 / 6.7.0.3 or later
Fixed in 6.4.0.136.6.56.7.0.3
Interim mitigation

Apply the relevant Cisco FMC software update/patch when available; until patched, restrict access to the FMC management interface to trusted networks only and train users to avoid clicking untrusted links.

Recommended fix High confidence

6.4.0.13+ (or latest 6.x/7.x stable release per branch - 6.6.5+ for 6.5-6.6 branch, 6.7.0.3+ for 6.7 branch)

  1. 1. Identify the current version of Cisco Firepower Management Center or Firepower Threat Defense by accessing the web interface and navigating to System > Help > About
  2. 2. For Firepower Management Center Virtual Appliance and Sourcefire Defense Center: Upgrade to version 6.4.0.13 or later (recommended: latest 6.x release)
  3. 3. For Firepower Threat Defense: If running < 6.4.0, upgrade to 6.4.0.13 or later; if running 6.5.0-6.6.4, upgrade to 6.6.5 or later; if running 6.7.0-6.7.0.2, upgrade to 6.7.0.3 or later
  4. 4. Download the appropriate upgrade package from Cisco.com Software Download center (requires valid CCO account)
  5. 5. Apply the upgrade via the web interface: Go to System > Updates, upload the upgrade package, and initiate the installation
  6. 6. After upgrade, verify the version change and test that the open redirect vulnerability is resolved by attempting benign redirect scenarios
Caveat Ensure compatibility with existing integrations and review release notes for any behavioral changes between versions; some upgrades may require intermediate steps

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Firepower Management Center Virtual Appliance Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-34764 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data