Secure Firewall Threat DefenseApplication · Cisco
CVE-2020-3317
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 ssl_inspection component of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to crash Snort instances. The vulnerability is due to insufficient input validation in the ssl_inspection component. An attacker could exploit this vulnerability by sending a malformed TLS packet through a Cisco Adaptive Security Appliance (ASA). A successful exploit could allow the attacker to crash a Snort instance, resulting in a denial of service (DoS) condition.
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 exists in the ssl_inspection component of Cisco Firepower Threat Defense (FTD) due to insufficient input validation. An unauthenticated remote attacker can send a malformed TLS packet through a Cisco ASA device, causing Snort instances to crash and resulting in a denial of service condition.
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
< 6.4.0.10>= 6.5.0, < 6.5.0.5CVSS 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
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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 Cisco FTD installationRun 'show version' or check the device management interface to confirm the device is running Cisco Firepower Threat Defense (FTD) software.Affected if The device is not running Cisco FTD.
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Check FTD version numberExecute 'show version' or access the FTD management console to display the installed software version.Affected if The installed version is less than 6.4.0.10, OR the installed version is 6.5.0 through 6.5.0.4 (versions 6.5.0 to 6.5.0.5 excluding 6.5.0.5).
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Verify ssl_inspection is enabledAccess the FTD configuration via CLI ('show running-config ssl-inspection') or through the management interface to check if the SSL/TSL inspection policy is active.Affected if ssl_inspection feature is enabled and the version is within the affected ranges.
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Check for Snort process crashesReview system logs and crash files by running 'show crashinfo' or checking /var/log/ directory for recent Snort-related crash entries.Affected if Recent Snort process crashes are present in the logs following malformed TLS traffic.
A system is affected if it runs Cisco FTD versions below 6.4.0.10 or between 6.5.0 and 6.5.0.4, has ssl_inspection enabled, and has experienced Snort crashes from malformed TLS packets.
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 data6.4.0.106.5.0.5
Apply the Cisco FTD software update/patch for CVE-2020-3317 when available. Until the patch is applied, consider implementing additional network-level controls to filter suspicious TLS traffic.
Fix this in Secure Firewall Threat Defense
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3317 — 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-2020-3317 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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