AsyncosOperating system · Cisco
CVE-2017-12218
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 malware detection functionality within Advanced Malware Protection (AMP) of Cisco AsyncOS Software for Cisco Email Security Appliances (ESAs) could allow an unauthenticated, remote attacker to cause an email attachment containing malware to be delivered to the end user. The vulnerability is due to the failure of AMP to scan certain EML attachments that could contain malware. An attacker could exploit this vulnerability by sending an email with a crafted EML attachment through the targeted device. A successful exploit could allow the attacker to bypass the configured ESA email message and content filtering and allow the malware to be delivered to the end user. Vulnerable Products: This vulnerability affects Cisco AsyncOS Software for Cisco ESA, both virtual and hardware appliances, that are configured with message or content filters to scan incoming email attachments on the ESA. Cisco Bug IDs: CSCuz81533.
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 Cisco Email Security Appliance (ESA) Advanced Malware Protection (AMP) allows crafted EML attachments containing malware to bypass configured message and content filters, resulting in delivery of malicious attachments to end users. The AMP scanning function fails to properly inspect certain EML attachments.
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
AsyncosOperating system
all versionsCVSS 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:3.0/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 checksWork through these to decide whether this CVE applies to you.
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Confirm Cisco ESA deviceLog into the ESA CLI and run 'show version' or access the web interface to verify the device model is an Email Security ApplianceAffected if The device is not a Cisco ESA - different product line
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Verify AsyncOS versionRun 'show version' in the ESA CLI to display the AsyncOS software versionAffected if The AsyncOS version is unpatched and falls within or below the vulnerable release range prior to CSCuz81533
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Confirm AMP is enabledRun 'amp' in the ESA CLI configuration mode, or check through the web interface under Security Services > Advanced Malware ProtectionAffected if AMP is disabled - the vulnerability only applies when AMP scanning is active
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Check EML attachment handlingReview message/content filter rules using 'filters' command in CLI or web interface to see if EML attachments are being scannedAffected if Filters are configured to inspect EML attachments - the flaw bypasses these when AMP fails
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Verify patch CSCuz81533 appliedCheck release notes or run 'show version' and compare build number against the fixed AsyncOS release for CSCuz81533Affected if The patch has not been applied and EML attachments are being delivered to users
User is affected if running an unpatched Cisco ESA with AsyncOS, AMP is enabled, and EML attachments are being processed through message/content filters.
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 dataApply the Cisco patch for CSCuz81533 to update AsyncOS Software. Review and verify that message/content filters are properly scanning EML attachments after the update.
Fix this in Asyncos
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-12218 — 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-2017-12218 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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