Secure Firewall Threat DefenseApplication · Cisco
CVE-2022-20745
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 web services interface for remote access VPN features of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a crafted HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, 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 web services interface for remote access VPN features of Cisco ASA and FTD Software allows unauthenticated remote attackers to cause device reload via crafted HTTPS requests due to improper input validation during HTTPS parsing.
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 and versionRun 'show version' on the device CLI to obtain the software version and confirm whether it is Cisco ASA or Firepower Threat Defense (FTD)Affected if The displayed version falls within any of the affected ranges: FTD < 6.4.0.15, 6.5.0 to < 6.6.5.2, 7.0.0 to < 7.0.2, or 7.1.0; ASA < 9.12.4.38, 9.13.0 to < 9.14.4, 9.15.0 to < 9.15.1.21, 9.16.0 to < 9.16.2.14, or 9.17.0 to < 9.17.1.7
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Confirm remote access VPN is enabledRun 'show vpn-sessiondb' or 'show run | include vpn' to check if any remote access VPN configuration exists (including AnyConnect, IPsec remote access, or client-based VPN)Affected if Remote access VPN is actively configured and the device accepts VPN connections
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Verify HTTPS web services interface is active on VPN interfacesRun 'show run http' or 'show running-config | include http' to check if the HTTPS server is enabled, then verify which interfaces accept HTTPS traffic using 'show run interface' combined with 'show ip' to identify externally accessible interfacesAffected if HTTPS server is enabled on any interface that is reachable from untrusted networks (such as outside or DMZ interfaces used for VPN access)
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Check for recent device reloads or crashesReview 'show crashinfo' or 'show logging' for unexpected reload events, and run 'show uptime' to confirm the device has not recently rebooted without administrator causeAffected if The device has experienced unexplained reloads or crashes that correlate with external HTTPS requests to VPN interfaces
You are affected if your device runs an affected ASA or FTD version, has remote access VPN configured with the HTTPS web services interface enabled on externally accessible interfaces, and is reachable via HTTPS from untrusted networks.
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 relevant Cisco security updates (software patches) to affected ASA and FTD installations. Until patched, consider implementing rate limiting on the VPN interface and restricting access to trusted networks.
ASA: 9.12.4.38, 9.14.4, 9.15.1.21, or 9.16.2.14 (depending on train) | FTD: 6.4.0.15, 6.6.5.2, 7.0.2, or 7.1.1+ (depending on train)
- 1. Identify the currently installed Cisco ASA or FTD software version using 'show version' command
- 2. Determine which software train your device is running (ASA version number or FTD version number)
- 3. Based on the affected version range, identify the minimum fixed version for your train
- 4. For FTD: If running 6.4.x train, upgrade to 6.4.0.15 or later; if 6.5.x/6.6.x, upgrade to 6.6.5.2 or later; if 7.0.x, upgrade to 7.0.2 or later; if 7.1.0, upgrade to a later version like 7.1.1 or 7.2.0
- 5. For ASA: If running 9.12.x, upgrade to 9.12.4.38 or later; if 9.13.x/9.14.x, upgrade to 9.14.4 or later; if 9.15.x, upgrade to 9.15.1.21 or later; if 9.16.x, upgrade to 9.16.2.14 or later
- 6. Download the appropriate fixed software image from Cisco.com (requires valid service contract)
- 7. Upload the new image to the device using FTP/SCP or through the management interface
- 8. Initiate the upgrade process using the 'install' command for FTD or appropriate upgrade method for ASA
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Secure Firewall Threat Defense
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-20745 — 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-2022-20745 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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