Adaptive Security ApplianceApplication · Cisco
CVE-2020-3303
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 Internet Key Exchange version 1 (IKEv1) feature 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. The vulnerability is due to improper management of system memory. An attacker could exploit this vulnerability by sending malicious IKEv1 traffic to an affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected 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 · high confidenceA memory management vulnerability in the IKEv1 feature of Cisco ASA and FTD allows unauthenticated remote attackers to send malformed IKEv1 packets that corrupt memory, causing a denial of service condition on the affected security appliance.
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
Adaptive Security ApplianceApplication
< 9.6.4.36
Adaptive Security Appliance SoftwareOperating system
>= 9.7, < 9.8.4.10>= 9.9, < 9.10.1.30>= 9.12, < 9.12.2.9
Secure Firewall Threat DefenseApplication
< 6.3.0.5>= 6.4.0, < 6.4.0.6CVSS 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 Cisco device type and softwareRun 'show version' or check the device management interface to determine if the device is running Cisco ASA or Firepower Threat Defense (FTD) softwareAffected if Device is Cisco ASA or FTD running any version
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Determine the ASA software versionRun 'show version | include Version' on the ASA CLI to obtain the exact software version numberAffected if Version is < 9.6.4.36 OR >= 9.7 and < 9.8.4.10 OR >= 9.9 and < 9.10.1.30 OR >= 9.12 and < 9.12.2.9
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Determine the FTD software versionRun 'show version' or check the FTD management console to obtain the exact software version numberAffected if Version is < 6.3.0.5 OR >= 6.4.0 and < 6.4.0.6
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Verify if IKEv1 is enabledRun 'show crypto isakmp sa' or check the configuration with 'show run | include isakmp' to see if IKEv1 is active on any interfaceAffected if IKEv1 is enabled and the version falls within the affected ranges listed above
The environment is affected if the device runs a vulnerable ASA or FTD version AND has IKEv1 protocol enabled on any interface.
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 data6.3.0.56.4.0.69.6.4.36
Apply the relevant Cisco security update (refer to Cisco advisory) or disable IKEv1 if not required, implementing rate limiting on IKEv1 ports as an interim mitigation.
Fix this in Adaptive Security Appliance
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-2020-3303 — 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-2020-3303 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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