Secure Firewall Threat DefenseApplication · Cisco
CVE-2022-20760
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 DNS inspection handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service condition (DoS) on an affected device. This vulnerability is due to a lack of proper processing of incoming requests. An attacker could exploit this vulnerability by sending crafted DNS requests at a high rate to an affected device. A successful exploit could allow the attacker to cause the device to stop responding, resulting in a 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 in the DNS inspection handler of Cisco ASA and FTD Software allows an unauthenticated remote attacker to cause denial of service by sending crafted DNS requests at high rates. The vulnerability stems from improper processing of incoming DNS requests, causing the affected device to stop responding.
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
< 6.4.0.15>= 6.5.0, < 6.6.5.2>= 7.0.0, < 7.0.2= 7.1.0
Adaptive Security Appliance SoftwareOperating system
< 9.12.4.38>= 9.13.0, < 9.14.4>= 9.15.0, < 9.15.1.21>= 9.16.0, < 9.16.2.14>= 9.17.0, < 9.17.1.7CVSS 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 the installed product typeLog into the device CLI and run 'show version' to confirm whether the device is running Cisco ASA Software or Cisco Firepower Threat Defense (FTD).Affected if Device is running ASA or FTD software.
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Determine the software versionRun 'show version' and locate the version number in the output. For FTD, also run 'show version' via the FMC or '.execute show version' in the FTD CLI.Affected if Version number matches the affected ranges: FTD < 6.4.0.15; >= 6.5.0 and < 6.6.5.2; >= 7.0.0 and < 7.0.2; or = 7.1.0. ASA < 9.12.4.38; >= 9.13.0 and < 9.14.4; >= 9.15.0 and < 9.15.1.21; >= 9.16.0 and < 9.16.2.14; or >= 9.17.0 and < 9.17.1.7.
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Check if DNS inspection is enabledRun 'show run all policy-map' or 'show run | include dns' to see if DNS inspection is configured. Also check active policy maps with 'show service-policy' to verify DNS inspection is actively applied to traffic.Affected if DNS inspection is enabled and applied to traffic flows.
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Verify DNS inspection configuration detailsRun 'show run policy-map type inspect dns' to view the DNS inspection policy configuration and confirm it is processing DNS traffic.Affected if DNS inspection policy exists and is bound to an interface or service policy.
Device is affected if it runs ASA or FTD software with a version in the affected ranges AND has DNS inspection enabled and applied to traffic.
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 · scoped6.4.0.156.6.5.27.0.2
Apply the Cisco software update for CVE-2022-20760 when available. As a temporary measure, rate-limit or block untrusted DNS traffic reaching the affected devices.
Upgrade to the first fixed version in your current branch: FTD 6.4.0.15, 6.6.5.2, 7.0.2, or 7.1.1+ | ASA 9.12.4.38, 9.14.4, 9.15.1.21, or 9.16.2.14
- Identify the current version of Cisco ASA or FTD by running 'show version' or checking the device management interface
- Determine the appropriate fixed version based on the current branch: for FTD: upgrade to 6.4.0.15, 6.6.5.2, 7.0.2, or 7.1.1+; for ASA: upgrade to 9.12.4.38, 9.14.4, 9.15.1.21, or 9.16.2.14
- Download the appropriate fixed release from Cisco Software Download center (requires Cisco CCO account)
- Review Cisco upgrade guides for your specific platform to ensure prerequisites are met
- Schedule a maintenance window as the device will need to be rebooted
- Upload the new image to the device and initiate the upgrade
- After upgrade completes, verify the new version is running with 'show version'
- Test basic connectivity and DNS inspection functionality to confirm the device is operational
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Secure Firewall Threat Defense
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-20760 — 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-2022-20760 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
- No weaponised exploit code, or anything meant to cause harm
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