AsyncosOperating system · Cisco
CVE-2016-1438
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 · uneditedCisco AsyncOS 9.7.0-125 on Email Security Appliance (ESA) devices allows remote attackers to bypass intended spam filtering via crafted executable content in a ZIP archive, aka Bug ID CSCuy39210.
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 confidenceCisco AsyncOS 9.7.0-125 on Email Security Appliance contains a filter bypass vulnerability where crafted executable content embedded within ZIP archives can bypass intended spam filtering mechanisms, allowing malicious attachments to reach end users.
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
= 9.7.0-125CVSS 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
- High
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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 Email Security Appliance is deployedIdentify if your environment includes a Cisco Email Security Appliance (ESA) or Cisco AsyncOS device. Check asset inventory or physically access the device web interface/cli.Affected if The device is a Cisco ESA running AsyncOS.
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Check AsyncOS versionLog into the ESA CLI and run the 'version' command, or check via the web interface under System Administration > Software Upgrade. Verify the exact AsyncOS version number.Affected if The version is exactly 9.7.0-125.
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Verify spam filtering is enabledIn the ESA web interface, navigate to Mail Policies > Spam Quarantine or use CLI command 'spamfilterconfig' to confirm spam filtering is active.Affected if Spam filtering is enabled and the AsyncOS version is 9.7.0-125.
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Check ZIP attachment filtering policyNavigate to Mail Policies > Attachment Filtering in the ESA web interface, or use CLI command 'attachmentfilter' to see if ZIP archives containing executable content are being filtered.Affected if ZIP attachment filtering for executable content is not configured or is being bypassed.
You are affected if you run Cisco Email Security Appliance with AsyncOS version 9.7.0-125 and have spam filtering enabled.
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 appropriate Cisco security update or upgrade to a patched AsyncOS version. Consider implementing additional content filtering policies for ZIP attachments containing executable content as a compensating control.
Fix this in Asyncos
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-1438 — 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-2016-1438 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data