Email Security ApplianceApplication · Cisco
CVE-2019-1844
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 certain attachment detection mechanisms of the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the filtering functionality of an affected device. The vulnerability is due to improper detection of certain content sent to an affected device. An attacker could exploit this vulnerability by sending certain file types without Content-Disposition information to an affected device. A successful exploit could allow an attacker to send messages that contain malicious content to users.
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 · moderate confidenceThe vulnerability exists in Cisco ESA's attachment detection logic. When certain file types are sent without the Content-Disposition header, the ESA fails to identify them as attachments and does not apply filtering policies. This allows malicious files to bypass content filters and 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
Email Security ApplianceApplication
= 11.1.0-131CVSS 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
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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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Verify ESA firmware versionAccess the ESA CLI or web interface and check the installed firmware version under System Administration > Firmware Upgrade or using the 'version' command in the CLIAffected if The installed version falls within the 11.1.0-131 range or matches the affected version specified in Cisco's advisory
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Inspect attachment filter policiesNavigate to Incoming Mail Policies or Outgoing Mail Policies in the ESA web interface and review the attachment filtering rules configured for your message filtersAffected if No filter rule specifically handles attachments missing the Content-Disposition header or the filter policy is not configured to inspect such attachments
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Test attachment detection with malformed headersSend a test email with an attachment that lacks the Content-Disposition header (such as a file sent with Content-Type only) and verify whether the ESA flags or blocks itAffected if The test attachment bypasses your configured filters and is delivered without being scanned or flagged as an attachment
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Review mail logs for attachment processingCheck the ESA mail logs (Mail Logs > Message Tracking) for emails with attachments that may be missing the Content-Disposition header and verify if content filters were appliedAffected if Emails with attachments lacking Content-Disposition are logged without filter actions or attachment scanning entries
Your environment is affected if the ESA runs a version within the affected range AND emails with attachments missing the Content-Disposition header are being delivered without being scanned or filtered.
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 Cisco's available patches for CVE-2019-1844 to the ESA firmware. Until patched, consider implementing additional outbound/inbound content filters at the gateway level or deploying secondary email security solutions to catch malformed attachments.
Fix this in Email 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-2019-1844 — 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-2019-1844 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