dbcve.org
Secure Firewall Threat DefenseApplication · Cisco

CVE-2024-20261

MEDIUM · 5.8 CVSS v3.1 Published 2024-05-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
67/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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
A vulnerability in the file policy feature that is used to inspect encrypted archive files of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass a configured file policy to block an encrypted archive file. This vulnerability exists because of a logic error when a specific class of encrypted archive files is inspected. An attacker could exploit this vulnerability by sending a crafted, encrypted archive file through the affected device. A successful exploit could allow the attacker to send an encrypted archive file, which could contain malware and should have been blocked and dropped at the Cisco FTD device.

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

A logic error in the file policy inspection engine of Cisco FTD fails to properly evaluate a specific class of encrypted archive files, allowing malware-laden archives to pass through despite a configured block policy. The vulnerability is exploitable by remote, unauthenticated attackers sending crafted encrypted archives through the affected device.

MitigationApply the vendor patch from Cisco when available; in the interim, implement additional network-layer controls to inspect or restrict encrypted archive traffic where possible.

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 Threat DefenseApplication
Affected:= 6.2.3= 6.2.3.1= 6.2.3.2= 6.2.3.3= 6.2.3.4= 6.2.3.5= 6.2.3.6= 6.2.3.7= 6.2.3.8= 6.2.3.9= 6.2.3.10= 6.2.3.11

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
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/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 device and product
    Run 'show version' or access the FTD management interface to confirm the device is Cisco Firepower Threat Defense (FTD)
    Affected if Device is not Cisco FTD (not affected)
  2. Check the FTD version
    Execute 'show version' and locate the software version string (e.g., 6.2.3, 6.2.3.5)
    Affected if Version matches 6.2.3.x from 6.2.3 through 6.2.3.11 (vulnerable)
  3. Determine if file policy inspection is enabled
    Access FTD management (Firepower Management Center or FTD CLI) and review the access control policy; look for File Policy or Intrusion and File Policy settings applied to the rule(s) handling traffic
    Affected if No file policy is applied to any access control rule (not affected in practice)
  4. Verify if archive file blocking is configured
    In the file policy settings, examine the file type rules for archive types (ZIP, RAR, 7z, etc.) and confirm if block action is set for those types
    Affected if Block action is configured for archive file types (would be bypassed if vulnerable)
  5. Confirm traffic inspection is active
    Check that the FTD is actively inspecting network traffic (not in passive/IDS-only mode) and that the relevant policy is applied to interfaces receiving the traffic
    Affected if Device is actively inspecting traffic with file policy applied

You are affected if running Cisco FTD version 6.2.3.x (6.2.3 through 6.2.3.11) with a file policy that includes archive blocking rules applied to actively inspected traffic.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch from Cisco when available; in the interim, implement additional network-layer controls to inspect or restrict encrypted archive traffic where possible.

Fix this in Secure Firewall Threat Defense Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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Scan for this in your stack

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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-2024-20261 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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